[TASK] Merge linkvalidator for 4.6

Changes included:
cb5fac3 [TASK] Prepare for release of TYPO3 4.6
22feb54 [BUGFIX] Pootle: Multi-line labels are not rendered
b4393ad [TASK] Fix version number of 4.6 branch
a195d11 [TASK] English XLIFF files should not contain target element
3b062e3 [TASK] Prepare merge for 4.6-RC1 (part 2)

Change-Id: I9144c82ffee4f94c5e7296cd54555215008a6e81
Resolves: #31201
Release: 4.6
Reviewed-on: http://review.typo3.org/6198
Reviewed-by: Philipp Gampe
Reviewed-by: Xavier Perseguers
Tested-by: Xavier Perseguers