Escaping of &'s and folder.jpg check.

Added escaping of &'s for XML info.  Discovered that if contents of .nfo had &'s, it would fail to parse.  This may need to go beyond just &'s, but I'm new at Python, so .... This likely needs to be added in both the TV and Movie parsers.  To test, create a .nfo file and for title, try to put "Angels & Demons" in the title brackets and XML will fail to parse. 

Added check for folder.jpg since this is still in spec for XBMC.

Thanks,
Brian