Fixed destuctors for various types of VST automation panel removal.
Automated signals correct disconection on panel removal.
When you load new VST plugin in the place of old one, while automation
is already connected and active there, this should not result in LMMS crash
or reuse of that old automation connections and automation window destructor
should not leave zombie VST plugins on application exit.
Signed-off-by: Tobias Doerffel <tobias.doerffel@gmail.com>
c2e9918c8a