[CLEANUP] backend: move LB algos to individual files
It was becoming painful to have all the LB algos in backend.c.
Let's move them to their own files. A few hashing functions still
need be broken in two parts, one for the contents and one for the
map position.
diff --git a/Makefile b/Makefile
index da5bee5..ed8cb27 100644
--- a/Makefile
+++ b/Makefile
@@ -459,6 +459,7 @@
src/time.o src/fd.o src/pipe.o src/regex.o src/cfgparse.o src/server.o \
src/checks.o src/queue.o src/client.o src/proxy.o src/proto_uxst.o \
src/proto_http.o src/stream_sock.o src/appsession.o src/backend.o \
+ src/lb_fwlc.o src/lb_fwrr.o src/lb_map.o \
src/stream_interface.o src/dumpstats.o src/proto_tcp.o \
src/session.o src/hdr_idx.o src/ev_select.o src/signal.o \
src/acl.o src/memory.o src/freq_ctr.o \