Merge branch 'stable-2.7' into stable-2.8

* stable-2.7:
  Use rev-parse to find gitdir when generating commit-msg hook hint

Conflicts:
	gerrit-server/src/main/java/com/google/gerrit/server/git/validators/CommitValidators.java

Change-Id: Ib6b05123e34b9a87a2e9bc735f05a443bdc13756