gui: remove dead code
gui refactoring: move gui.canvas to gui.comp.miccanvas and gui.instrmodel to gui.model

hopefully will make things more clear and organised
gui: small fixes

Fix stop actuators after refactoring

Make sure the stream should_update flag is up-to-date when adding/removing streams

Avoid dead object when removing stream entry with histogram
gui: some TODO for menu
gui: deduplicate stop motion

Use only the method off the model, the main GUI code doesn't need to know the internal details
gui: add a .debug VA to the main data model, and use it

This avoids the miccanvas to have to care about the menu (directly)
gui: clean up stream entries

Use more VAConnectors
Remove GUI for not yet existing funcitonality