Follow-up to bug #12154: renamed t3lib_MessageQueue to t3lib_FlashMessageQueue, changed some some function names in t3lib_flashmessages and t3lib_FlashMessageQueue.

git-svn-id: https://svn.typo3.org/TYPO3v4/Core/trunk@6133 709f56b5-9817-0410-a4d7-c38de5d9e867