Merge branch 'wp/sha1-name-negative-match'

A new "<branch>^{/!-<pattern>}" notation can be used to name a
commit that is reachable from <branch> that does not match the
given <pattern>.

* wp/sha1-name-negative-match:
object name: introduce '^{/!-<negative pattern>}' notation
test for '!' handling in rev-parse's named commits

diff --cc Documentation/revisions.txt
Simple merge

diff --cc sha1_name.c
Simple merge

diff --cc t/t1511-rev-parse-caret.sh
Simple merge