Additional concessions to make Vala generate correct code for these hooks
Not sure why this compiled before...?
Vala expects ref functions to be chainable, a behavior which is just now causing me problems for reasons I don't entirely understand or care about.
Fix some nasty memory corruption bug which was pissing me off until I realized where the damn thing was
Integrate CanvasTool/BrushTool into CanvasWidget, giving us drawing support again