Merge branch 'stable-2.8' into stable-2.9

* stable-2.8:
  Executing CherryPick.writeCherryPickCommit() in a transaction.
  Bump API version to 2.8.6
  Release notes for Gerrit 2.8.6
  Add missing 'link:' in 2.8.5 release notes
  ChangeMergeQueue: Fix race condition

Conflicts:
	VERSION
	gerrit-plugin-archetype/pom.xml
	gerrit-plugin-gwt-archetype/pom.xml
	gerrit-plugin-gwtui/pom.xml
	gerrit-plugin-js-archetype/pom.xml
	gerrit-server/src/main/java/com/google/gerrit/server/git/strategy/CherryPick.java

Change-Id: I06fba0020457de66f68ac2b5675e9d57bf75d750