ext/lcs/Makefile.am: Fix so that the lcs colorspace plugin doesn't conflict with the internal colorspace plugin.

Original commit message from CVS:
* ext/lcs/Makefile.am:  Fix so that the lcs colorspace plugin
doesn't conflict with the internal colorspace plugin.
* gst-libs/gst/audio/make_filter:  Use `` instead of $() to
satisfy the crappy-ass shell shipped by a certain vendor.
* gst/videofilter/make_filter: same (bug #135299)