Add pixel density concept to the code. So, it draw about the same size on
mdpi and hdpi devices.

Update the UI assets for mdpi

Fix a issue that GLSurfaceView didn't call onPause and onResume in Camera.
Refactor. Improve the drawing and animation.

Also fix the RawTexture unsupported operation bugs and the NullPointerException
in GLRootView.

Change-Id: I7aeadcad72d64a665828a6bb4f0f73e685fde632
60 files changed