Original commit message from CVS:
* check/gst/gstghostpad.c: (GST_START_TEST), (gst_ghost_pad_suite):
Added check for bug #317341

* gst/gstbuffer.c:
* gst/gstbuffer.h:
Some more spiffifying.

* gst/gstghostpad.c: (gst_ghost_pad_do_link):
Call peer linkfunction if we are a source pad. Totally fixes
#317341

* gst/gstpad.c:
Update docs, source pads should call the peer linkfunction
so they can atomically perform the pad link.