DOC: assorted typo fixes in the documentation and Makefile

This is another round of cleanups in various docs and comments in the
Makefile.

(cherry picked from commit 2a950d02a951715447d4068ec6689a842d452aaa)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit 99ac71d7fff3cc11d70fb2de2758daf69cd85e42)
[wt: drop changes not for 2.0]
Signed-off-by: Willy Tarreau <w@1wt.eu>
diff --git a/doc/regression-testing.txt b/doc/regression-testing.txt
index 320c51c..1b6c21d 100644
--- a/doc/regression-testing.txt
+++ b/doc/regression-testing.txt
@@ -131,7 +131,7 @@
     #   BUG/MINOR: spoe: Initialize variables used during conf parsing before any check
 
     #   Some initializations must be done at the beginning of parse_spoe_flt to avoid
-    #   segmentaion fault when first errors are caught, when the "filter spoe" line is
+    #   segmentation fault when first errors are caught, when the "filter spoe" line is
     #   parsed.
 
     haproxy h1 -conf-BAD {} {