DOC: Documentation for hashing function, with test results.

Summary:
Added a document for hashing under internal docs explaining
hashing in haproxy along with the results of tests under the test
folder.

These documents together explain the motivation for adding
options for hashing algorithms with the option of enabling or
disabling of avalanche.
diff --git a/tests/hashing-results.txt b/tests/hashing-results.txt
new file mode 100644
index 0000000..d2dbf59
--- /dev/null
+++ b/tests/hashing-results.txt
@@ -0,0 +1,314 @@
+These are the result of tests conducted to determine efficacy of hashing
+algorithms and avalache application in haproxy. All results below were
+generated using version 1.5. See the document on hashing under internal docs
+for a detailed description on the tests the methodology and interpretation
+of the results.
+
+The following was the set up used
+
+(a) hash-type consistent/map-bases
+(b) avalanche on/off
+(c) balanche host(hdr)
+(d) 3 criteria for inputs
+    - ~ 10K requests, including duplicates
+    - ~ 46K requests, unique requests from 1 MM requests were obtained
+    - ~ 250K requests, including duplicates
+(e) 17 servers in backend, all servers were assigned the same weight
+
+The results can be interpreted across 3 dimensions corresponding to input
+criteria (a)/(b) and (d) above
+
+== 10 K requests ==
+
+=== Consistent with avalanche ===
+
+Servers SDBM    DJB2    WT6
+-----------------------------
+1       576     637     592
+2       552     608     600
+3       539     559     551
+4       578     586     493
+5       534     555     549
+6       614     607     576
+7       519     556     554
+8       591     565     607
+9       529     604     575
+10      642     550     678
+11      537     591     506
+12      568     571     567
+13      589     606     572
+14      648     568     711
+15      645     557     603
+16      583     627     591
+17      699     596     618
+-----------------------------
+Std Dev 48.95   26.29   51.75
+
+=== Consistent without avalanche ===
+
+Servers SDBM    DJB2    WT6
+-----------------------------
+1       612     627     579
+2       631     607     563
+3       585     605     604
+4       594     502     518
+5       583     526     602
+6       589     594     555
+7       591     602     511
+8       518     540     623
+9       550     519     523
+10      600     637     647
+11      568     536     550
+12      552     605     645
+13      547     556     564
+14      615     674     635
+15      642     624     618
+16      575     585     609
+17      591     604     597
+-----------------------------
+Std Dev 30.71   45.97   42.52
+
+=== Map based without avalanche ===
+
+Servers SDBM    DJB2    WT6
+-----------------------------
+1       602     560     598
+2       576     583     583
+3       579     624     593
+4       608     587     551
+5       579     549     588
+6       582     560     590
+7       553     616     562
+8       568     600     551
+9       594     607     620
+10      574     611     635
+11      578     607     603
+12      563     581     547
+13      604     531     572
+14      621     606     618
+15      600     561     602
+16      555     570     585
+17      607     590     545
+-----------------------------
+Std Dev 19.24   25.56   26.29
+
+=== Map based with avalanche ===
+
+Servers SDBM    DJB2    WT6
+-----------------------------
+Servers SDBM    DJB2    WT6
+1       548     641     597
+2       612     563     655
+3       596     536     595
+4       609     574     537
+5       586     610     570
+6       600     568     562
+7       589     573     578
+8       584     549     573
+9       561     636     603
+10      607     553     603
+11      554     602     616
+12      560     577     568
+13      597     534     570
+14      597     647     570
+15      563     581     647
+16      575     647     565
+17      605     552     534
+-----------------------------
+Std Dev 20.23   37.47   32.16
+
+== Uniques in 1 MM ==
+
+=== Consistent with avalanche ===
+
+Servers SDBM    DJB2    WT6
+-----------------------------
+1       2891    2963    2947
+2       2802    2849    2771
+3       2824    2854    2904
+4       2704    2740    2763
+5       2664    2699    2646
+6       2902    2876    2935
+7       2829    2745    2730
+8       2648    2768    2800
+9       2710    2741    2689
+10      3070    3111    3106
+11      2733    2638    2589
+12      2828    2866    2885
+13      2876    2961    2870
+14      3090    2997    3044
+15      2871    2879    2827
+16      2881    2727    2921
+17      2936    2845    2832
+-----------------------------
+Std Dev 121.66  118.59  131.61
+
+=== Consistent without avalanche ===
+
+Servers SDBM    DJB2    WT6
+-----------------------------
+1       2879    2930    2863
+2       2835    2856    2853
+3       2875    2741    2899
+4       2720    2718    2761
+5       2703    2754    2689
+6       2848    2901    2925
+7       2829    2756    2838
+8       2761    2779    2805
+9       2719    2671    2746
+10      3015    3176    3079
+11      2620    2661    2656
+12      2879    2773    2713
+13      2829    2844    2925
+14      3064    2951    3041
+15      2898    2928    2877
+16      2880    2867    2791
+17      2905    2953    2798
+-----------------------------
+Std Dev 107.65  125.2   111.34
+
+=== Map based without avalanche ===
+
+Servers SDBM    DJB2    WT6
+-----------------------------
+1       2863    2837    2923
+2       2966    2829    2847
+3       2865    2803    2808
+4       2682    2816    2787
+5       2847    2782    2815
+6       2910    2862    2862
+7       2821    2784    2793
+8       2837    2834    2796
+9       2857    2891    2859
+10      2829    2906    2873
+11      2742    2851    2841
+12      2790    2837    2870
+13      2765    2902    2794
+14      2870    2732    2900
+15      2898    2891    2759
+16      2877    2860    2863
+17      2840    2842    2869
+-----------------------------
+Std Dev 64.65   45.16   43.38
+
+=== Map based with avalanche ===
+
+Servers SDBM    DJB2    WT6
+-----------------------------
+1       2816    2859    2895
+2       2841    2739    2789
+3       2846    2903    2888
+4       2817    2878    2812
+5       2750    2794    2852
+6       2816    2917    2847
+7       2792    2782    2786
+8       2800    2814    2868
+9       2854    2883    2842
+10      2770    2854    2855
+11      2851    2854    2837
+12      2910    2846    2776
+13      2904    2792    2882
+14      2984    2767    2854
+15      2766    2863    2823
+16      2902    2797    2907
+17      2840    2917    2746
+-----------------------------
+Std Dev 58.39   52.16   43.72
+
+== 250K requests ==
+
+=== Consistent with avalanche ===
+
+Servers SDBM    DJB2    WT6
+-----------------------------
+1       14182   12996   20924
+2       14881   18376   8901
+3       13537   17935   13639
+4       11031   12582   19758
+5       15429   10084   12112
+6       18712   12574   14052
+7       14271   11257   14538
+8       12048   18582   16653
+9       10570   10283   13949
+10      11683   13081   23530
+11      9288    14828   10818
+12      10775   13607   19844
+13      10036   19138   15413
+14      31903   15222   11824
+15      21276   11963   10405
+16      17233   23116   11316
+17      11437   12668   10616
+-----------------------------
+Std Dev 5355.95 3512.39 4096.65
+
+=== Consistent without avalanche ===
+
+Servers SDBM    DJB2    WT6
+-----------------------------
+1       12411   17833   11831
+2       14213   11165   14833
+3       11431   10241   11671
+4       14080   13913   20224
+5       10886   12101   14272
+6       15168   12470   14641
+7       18802   12211   10164
+8       18678   11852   12421
+9       17468   10865   17655
+10      19801   28493   13221
+11      10885   20201   13507
+12      20419   11660   14078
+13      12591   18616   13906
+14      12798   18200   24152
+15      13338   10532   14111
+16      11715   10478   14759
+17      13608   17461   12846
+-----------------------------
+Std Dev 3113.33 4749.97 3256.04
+
+=== Map based without avalanche ===
+
+Servers SDBM    DJB2    WT6
+-----------------------------
+1       14660   12483   11472
+2       11118   11552   12146
+3       15407   19952   11032
+4       15444   12218   14572
+5       22091   11434   13738
+6       18273   17587   21337
+7       10527   16784   15118
+8       13013   12010   17195
+9       15754   9886    14611
+10      13758   11613   14844
+11      19564   16453   17403
+12      9692    17246   14469
+13      13905   11885   20024
+14      19401   15350   10611
+15      11889   25485   11172
+16      13846   13928   12109
+17      9950    12426   16439
+-----------------------------
+Std Dev 3481.45 3847.74 3031.93
+
+=== Map based with avalanche ===
+
+Servers SDBM    DJB2    WT6
+-----------------------------
+1       15546   11454   12871
+2       15388   11464   17587
+3       11767   15527   14785
+4       15843   13214   11420
+5       11129   12192   15083
+6       15647   17875   11051
+7       18723   13629   23006
+8       10938   11295   11223
+9       12653   17202   23347
+10      10108   12867   14178
+11      12116   11190   20523
+12      14982   12341   11881
+13      13221   13929   11828
+14      17642   19621   15320
+15      12410   26171   11721
+16      25075   14764   13544
+17      15104   13557   8924
+-----------------------------
+Std Dev 3521.83 3742.21 4101.2