Merge pull request #20 from donny-dont/cleanup

Cleanup RasterizerState
Disable BlendState and RasterizerState equality tests and operator.

Signed-off-by: John McCutchan <john@johnmccutchan.com>
Add aspectRatio getter to Viewport.

Signed-off-by: John McCutchan <john@johnmccutchan.com>
Remove name mapping from GraphicsDevice.

Signed-off-by: John McCutchan <john@johnmccutchan.com>
Add proper shader program asset importer.

Signed-off-by: John McCutchan <john@johnmccutchan.com>
Merge upstream master branch. Adding back in aspectRatio to Viewport.