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/management.txt b/doc/management.txt
index 2ba460d..922c133 100644
--- a/doc/management.txt
+++ b/doc/management.txt
@@ -1507,7 +1507,7 @@
   level "admin".
 
 disable dynamic-cookie backend <backend>
-  Disable the generation of dynamic cookies fot the backend <backend>
+  Disable the generation of dynamic cookies for the backend <backend>
 
 disable frontend <frontend>
   Mark the frontend as temporarily stopped. This corresponds to the mode which