Original commit message from CVS:
this patch fixes arts and artsd compilation problems. this is necessary for make
dist to work. i know plugins are being moved, though, this needs to be ported to
the -plugins module.
* experimental and broken selection now use GST_CHECK_FEATURE, for what it's worth
* crucial fixes to arts m4's that need backporting to autostars and -plugins
* make gst-feature less frantic in reporting missing plugins
* cleanups and misc arts fixes
