Merge branch 'jk/trailer-fixes' into maint

"git interpret-trailers" and its underlying machinery had a buggy
code that attempted to ignore patch text after commit log message,
which triggered in various codepaths that will always get the log
message alone and never get such an input.

* jk/trailer-fixes:
append_signoff: use size_t for string offsets
sequencer: ignore "---" divider when parsing trailers
pretty, ref-filter: format %(trailers) with no_divider option
interpret-trailers: allow suppressing "---" divider
interpret-trailers: tighten check for "---" patch boundary
trailer: pass process_trailer_opts to trailer_info_get()
trailer: use size_t for iterating trailer list
trailer: use size_t for string offsets

diff --cc Documentation/git-interpret-trailers.txt
Simple merge

diff --cc commit.c
Simple merge

diff --cc commit.h
Simple merge

diff --cc pretty.c
Simple merge

diff --cc ref-filter.c
Simple merge

diff --cc sequencer.c
Simple merge

diff --cc sequencer.h
Simple merge

diff --cc t/t6300-for-each-ref.sh
Simple merge

diff --cc t/t7501-commit.sh
Simple merge

diff --cc trailer.h
Simple merge