Subcanvas progress

I'm always impressed by how quick you can get stuff working in Smalltalk and Squeak. I spent a couple of hours over the last weekend getting events working in Subcanvas. I haven't touched it for a month now as I've only just come back from a 3-week holiday with my family.

So now Subcanvas can process left mouse button clicks. I coded up a small demo where the mouse click handler drew small 5mm x 5mm squares on the screen. You can add a child canvas, and the events and redrawing works in the simple case.