Original commit message from CVS:
Change GST_DEBUG_FUNCPTR() to return a pointer of the same type that it
is called with. Fix lots of warnings due to change.
Original commit message from CVS:
added (hopefully) compatible cothreads emulation by using GThreads.
use '--gst-scheduler=basicgthread' to try it out
includes bugfix for opt to call do_cothreads_init when using threads