[TASK] Upgrade CodeMirror to v.4.4

Change-Id: I2e4010c1f3fb2defcd3911ba7499fb23a85c249f
Reviewed-on: http://review.typo3.org/31917
Reviewed-by: Xavier Perseguers <xavier@typo3.org>
Tested-by: Xavier Perseguers <xavier@typo3.org>