TYPO3 Core

The attached patch introduces an API for the integration of ExtDirect into TYPO3. The API is very simply to use and supports the definition of namespaces like TYPO3.Backend. The last named Namespace will be loaded by default in the TYPO3 Backend. You can find an example inside the attached demo extension that demonstrates the usage of the API within an extension.

BTW: This is a result from the T3UXW09 and was already reviewed by Benni and Sebastian. Also it's a prerequisite for several followup patches to the enhanced integration of ExtJS into the TYPO3 backend.

(issue imported from #M13313)