[TASK] Raise compatibility to TYPO3 4.7.99 (known to work)

git-svn-id: https://svn.typo3.org/TYPO3v4/Extensions/ttnews_rss_import/trunk@76661 735d13b6-9817-0410-8766-e36946ffe9aa
[TASK] Cleanup and monster import from Jigal's fixes

git-svn-id: https://svn.typo3.org/TYPO3v4/Extensions/ttnews_rss_import/trunk@76664 735d13b6-9817-0410-8766-e36946ffe9aa
[BUGFIX] #6589: Problems with category and field mapping settings

git-svn-id: https://svn.typo3.org/TYPO3v4/Extensions/ttnews_rss_import/trunk@76667 735d13b6-9817-0410-8766-e36946ffe9aa