Don't install static libs for plugins. Fixes #550851 for ugly.

Don't install static libs for plugins. Fixes #550851 for ugly.

Original commit message from CVS:
* ext/a52dec/Makefile.am:
* ext/amrnb/Makefile.am:
* ext/cdio/Makefile.am:
* ext/dvdnav/Makefile.am:
* ext/dvdread/Makefile.am:
* ext/lame/Makefile.am:
* ext/mad/Makefile.am:
* ext/mpeg2dec/Makefile.am:
* ext/sidplay/Makefile.am:
* gst/ac3parse/Makefile.am:
* gst/asfdemux/Makefile.am:
* gst/dvdlpcmdec/Makefile.am:
* gst/dvdsub/Makefile.am:
* gst/iec958/Makefile.am:
* gst/mpegaudioparse/Makefile.am:
* gst/mpegstream/Makefile.am:
* gst/realmedia/Makefile.am:
* gst/synaesthesia/Makefile.am:
Don't install static libs for plugins. Fixes #550851 for ugly.