Original commit message from CVS: debugging session with wim
Original commit message from CVS: mutexes want to be free, too
Original commit message from CVS: Fix bug when joining threads.
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