Instrument modification clearing hooked up
Kind of shows modified status properly
Updated todo
Removed context from contour instance fields
Don't have context as instrument field
Add new Scene class to wrap the output context and destination node etc.
Starting to move stuff into background page; reorganised background page
Moved instrument and scene to background page
Window pages hold reference to background page structure
Fix resizing problem with inspectors open
Wrapped up keyboard window stuff in a class