check/Makefile.am: re-enable tests now that leaks are plugged

check/Makefile.am: re-enable tests now that leaks are plugged

Original commit message from CVS:
* check/Makefile.am:
re-enable tests now that leaks are plugged
* check/gst/gst.c:
* check/gst/gstbin.c:
* check/gst/gstpipeline.c:
add some more tests while fixing leaks
* common/check.mak:
make sure binaries are uptodate when valgrinding/gdbing
* gst/gst.c:
* gst/gstelementfactory.c:
remove a ref too many, and add a FIXME for when we get
round to disposing of classes
* gst/gstplugin.c:
fix the refcounting when loading a plugin from a file and
the code pretends that the pointer is the same even though
of course it can change
* gst/gstpluginfeature.c:
unref plugins marked cached (a bit confusing as a name)
as the docs state should be done
various doc additions to explain refcounting
* gst/gstregistry.c:
* gst/gstregistryxml.c:
debugging