Consolidate codepaths that inspect log-message-to-be and decide to
add a new Signed-off-by line in various commands.
* bc/append-signed-off-by:
git-commit: populate the edit buffer with 2 blank lines before s-o-b
Unify appending signoff in format-patch, commit and sequencer
format-patch: update append_signoff prototype
t4014: more tests about appending s-o-b lines
sequencer.c: teach append_signoff to avoid adding a duplicate newline
sequencer.c: teach append_signoff how to detect duplicate s-o-b
sequencer.c: always separate "(cherry picked from" from commit body
sequencer.c: require a conforming footer to be preceded by a blank line
sequencer.c: recognize "(cherry picked from ..." as part of s-o-b footer
t/t3511: add some tests of 'cherry-pick -s' functionality
t/test-lib-functions.sh: allow to specify the tag name to test_commit
commit, cherry-pick -s: remove broken support for multiline rfc2822 fields
sequencer.c: rework search for start of footer to improve clarity
900c8ecb5c