gst/gstelementfactory.c: set the factory in the class struct, so gst_element_get_fact...

gst/gstelementfactory.c: set the factory in the class struct, so gst_element_get_factory actually works

Original commit message from CVS:
* gst/gstelementfactory.c: (gst_element_register):
set the factory in the class struct, so gst_element_get_factory
actually works
* gst/parse/grammar.y:
set element to playing when it gets unlocked as we can't rely on the
bin state - all elements in the bin state might still be locked in
NULL)