#70 Plugin GUI: open/close state isn't remembered by the host

[minimalist]

I've tested it with Ableton (there it works) and with Maschine (there not).
If your host-project has 2 tracks and in one Ctrlr is loaded (and GUI is open) - then you leave this track and select the other track... then if you re-select again the track where Ctrlr is hosted - the GUI of Ctrlr is not visible anymore (it seems that the GUI is closed, but actually it isn't). When you want to reopen the Ctrlr GUI you have to double click the GUI open/close option in your host (first click=close GUI (because actually is was opened), second click=open GUI again).