Original commit message from CVS:
Added support for live sources and other elements that
cannot do preroll.
Updated design docs, added live-source design doc.
Implemented live source functionality in basesrc
Fix error condition in _bin_get_state()
Implement live source handling in -launch.
Added check for live sources.
Fixed case in GstBin where elements were changed state
multiple times.
Original commit message from CVS:
Added state change code.
Added/updated docs.
Added sink base class, make fakesink extend the base class.
Small cleanups in GstPipeline.