[TASK] Localize Extension Manager configuration options

Change-Id: I347583959220ada0ca8b11e7d98e6a2a38e3bf61
Reviewed-on: http://review.typo3.org/35676
Reviewed-by: Xavier Perseguers <xavier@typo3.org>
Tested-by: Xavier Perseguers <xavier@typo3.org>