More TODOs.
Added the beginning of the Mac OS X Area implementation. Also fixed the long-broken Mac OS X build.
Attempted to add the Area bare bones and resizing code to the Mac OS X backend. It complains that initWithFrame: is not implemented...
When we created our delegate and view classes on Mac OS X, it turned out we were accidentally subclassing the metaclass (of NSObject and NSView, respectively), not the actual superclass itself. Fixed tha. This also fixed that mysterious objc_new()/[object init] not working on the delegate class problem.
Fixed Mac OS X Area setAreaSize() not working: I was using the NSWindow setFrame:display: selector instead of sending the two NSView setFrame: and display methods separately.
Implement Mac OS X AreaHandler.Paint().
Fixed flaky redraw in Mac OS X Areas.
Implemented Area mouse events on Mac OS X. Also fixed a few other things left behind in the previous commits. Also more TODOs.
Added key events to Mac OS X Areas. Now Area is feature-complete (but buggy) on all platforms :D Also more TODOs.
Updated the documentation: Area now works on all platforms, Modifiers behavior on both left and right keys simultaneously is undefined for now, and the way to create custom Controls no longer involves embedding Area.
Marked Windows MouseEvent.Held as not done; oops.
Added right Command to events_darwin.go.