remove win32 path stuff (not used anymore?) check for core 0.3.1 not 0.3.0 update...

remove win32 path stuff (not used anymore?) check for core 0.3.1 not 0.3.0 update Xv check for Xv_pic systems include...

Original commit message from CVS:
* remove win32 path stuff (not used anymore?)
* check for core 0.3.1 not 0.3.0
* update Xv check for Xv_pic systems
include text explaining it so check is not removed (again)
* remove GLIB_ vars since we don't set those vars
they are assumed to be in GST_ vars
* fix festival check - lib not used, just net connection to a server
* better FLAC test
* remove some core configure.ac leftovers