[BUGFIX] Fix wrong image reference in ext:taskcenter

Path to image does not exists, rename it to the existing png file.

Furthermore this patch shortens a few namespaces and uses
GeneralUtility::quoteJSvalue for the url in openInNewWindow function.

Resolves: #66584
Releases: master
Change-Id: I9b17aafae6a4f94ddefa5d012c447b8eacc0495d
Reviewed-on: http://review.typo3.org/38910


Reviewed-by: Mathias Schreiber <mathias.schreiber@wmdb.de>
Tested-by: Mathias Schreiber <mathias.schreiber@wmdb.de>
Reviewed-by: Michael Oehlhof <typo3@oehlhof.de>
Tested-by: Michael Oehlhof <typo3@oehlhof.de>
Reviewed-by: Xavier Perseguers <xavier@typo3.org>
Tested-by: Xavier Perseguers <xavier@typo3.org>