ext/theora/: Take a 2nd stab at handling libtheora granulepos changes in the decoder and parser by inspecting the bit...

Original commit message from CVS:
* ext/theora/gsttheoradec.h:
* ext/theora/gsttheoraparse.h:
* ext/theora/theoradec.c:
* ext/theora/theoraparse.c:
Take a 2nd stab at handling libtheora granulepos changes in the decoder
and parser by inspecting the bitstream version of the incoming data.