[TASK] Hide clipboard menu selector if clipboard is empty

With this patch the clipboard menu selector becomes visible
if the clipboard is not empty.

Resolves: #68142
Releases: master
Change-Id: I9a0ec271da0b3e5aeeb97cff0b728f8faead9d72
Reviewed-on: http://review.typo3.org/41248


Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>