PenDemo: clean up logs
PenDemo: update log
PenDemo: remove useless code
PenDemo: refactoring code of BrushManager.processFastScribble()
PenDemo: remove useless code
PenDemo: rename BrushManager.processFastScribble() to applyFastScribble()
PenDemo: add BrushManager.mDelayedLeaveScribbleModeAndUpdateBrushView to control the leaving of scribble mode