[LAD] RFC: LV2 state

[David Robillard]

Here is the current version of the LV2 state extension, which defines
the model for plugin state, and a mechanism for saving and restoring it:

http://lv2plug.in/ns/ext/state

It's time to tag this one as stable, unless anyone can see any issues
(i.e. speak now, or forever hold your peace).  If anyone has the time to
give it a quick read-through, feedback would be appreciated.  I have
done a lot of work on the documentation lately, hopefully everything
should be clear.

This is currently implemented in Ardour 3 SVN, QTractor SVN, and a patch
for LinuxSampler SVN is available here:

http://drobilla.net/files/linuxsampler_lv2_state_0_4.diff

Thanks,

-dr