Fallback detection patch
|Reported by:||SF/buddha_||Owned by:||sev-|
Makes fallback detection use an encapsulated version of the game descriptions because we'll need dynamic content generation for the game descriptions at least in the AGI engine's fallback detector.
Before this patch you couldn't generate strings on the fly (e.g. read them from a file) and put the into game descriptions because the c-strings there were const char *.
Also modifies all engines to use the encapsulated version of game description when using detectBestMatchingGame and handle its deallocation.
Ticket imported from: #1733764. Ticket imported from: patches/795.