- Changed canvas coordinate system to match UI coord system (origin at top left, y axis down)
- Changed mouse coordinate system to match UI and canvas
- No need to pass width/height to ui_begin_frame() anymore
- Remove the need for client apps to explicitly link with all dependent libs and frameworks
- Don't require redistributing libEGL/libGLES if not used, by linking them with '-weak-l' option
- Change examples build scripts accordingly