LV2 support

by drobilla for GStreamer

The goal of this project is to implement a bridge plugin to allow the use of LV2 plugins with gstreamer. LV2 is the successor to LADSPA, which is already supported by gstreamer. LV2 transforms LADSPA into a more flexible specification which allows plugins to provide greatly enhanced functionality compared to what is possible with LADSPA. Several projects have created LV2 plugins which go beyond the capabilities of LADSPA; support for LV2 plugins in gstreamer would allow access to this new functionality, as well as all future work of the LV2 community.