Original commit message from CVS:
* add 'toolsdir' to the pc files
* add our first plugin test, which involves simply running gst-compprep,
which in the course of creating the completion registry instantiates every
plugin. gst-register is run first.
Original commit message from CVS:
eventually there will be an autopluggins test suite here that will verify plugin caps.
for now what we have was taken from gstreamer/tests/.