Description of problem: Implement 'ESC' key to close editor option in user config popup. If enabled, editor closes when ESC key is pressed. If not enabled(default), ESC key does nothing.
Implementation done. See https://github.com/zanata/zanata/commit/f30989daae98296ad53573fd1f490baf6eae33b2
VERIFIED with Zanata version 1.4.2-SNAPSHOT (20111019-0917)