Merge branch 'jc/format-patch-reroll'

Teach "format-patch" to prefix v4- to its output files for the
fourth iteration of a patch series, to make it easier for the
submitter to keep separate copies for iterations.

* jc/format-patch-reroll:
format-patch: give --reroll-count a short synonym -v
format-patch: document and test --reroll-count
format-patch: add --reroll-count=$N option
get_patch_filename(): split into two functions
get_patch_filename(): drop "just-numbers" hack
get_patch_filename(): simplify function signature
builtin/log.c: stop using global patch_suffix
builtin/log.c: drop redundant "numbered_files" parameter from make_cover_letter()
builtin/log.c: drop unused "numbered" parameter from make_cover_letter()

diff --cc Documentation/git-format-patch.txt
index 259dce49945089de03ad2c0ac8ae8e56cfdc04e0,ae3212e8d8b1bcdbf19c37295b8d993c33bb3e9b..9a914d01597011d6703e6b560d707c221cba177e
--- 1/Documentation/git-format-patch.txt
--- 2/Documentation/git-format-patch.txt
+++ b/Documentation/git-format-patch.txt
@@@ -18,9 -18,9 +18,9 @@@ SYNOPSI
                   [--start-number <n>] [--numbered-files]
                   [--in-reply-to=Message-Id] [--suffix=.<sfx>]
                   [--ignore-if-in-upstream]
-                  [--subject-prefix=Subject-Prefix]
+                  [--subject-prefix=Subject-Prefix] [(--reroll-count|-v) <n>]
                   [--to=<email>] [--cc=<email>]
 -                 [--cover-letter] [--quiet]
 +                 [--cover-letter] [--quiet] [--notes[=<ref>]]
                   [<common diff options>]
                   [ <since> | <revision range> ]
  

diff --cc builtin/log.c
Simple merge

diff --cc log-tree.c
Simple merge

diff --cc revision.h
Simple merge

diff --cc t/t4014-format-patch.sh
Simple merge