Merge branch 'stable-2.8'

* stable-2.8:
  Codemirror: Add support for Groovy mode
  Codemirror: Add support for Clojure mode
  Codemirror: Add support for Lisp mode
  Codemirror: Add support for ruby mode
  Codemirror: Add support for perl mode

Conflicts:
	gerrit-server/src/main/java/com/google/gerrit/server/DefaultFileExtensionRegistry.java

Change-Id: Icf61f85ea50b02d63a222973d0781afe67e03ee6