[TYPO3-core] RFC #1318: 'removeTag' does not remove closing tags

[Xavier Perseguers]

FYI, committed to

- trunk (rev. 9137)
- TYPO3_4-4 (rev. 9138)
- TYPO3_4-3 (rev. 9139)
- TYPO3_4-2 (rev. 9140)

and for the sake of completeness as the bug was reported for TYPO3 3.8:

- TYPO3_4-1 (rev. 9141)
- TYPO3_4-0 (rev. 9142)
- TYPO3_3-8-1 (rev. 9143)
- TYPO3_3-8 (rev. 9144)

Cheers :D

Xavier