Small fix for previous commit.

Added support for querying client attribute state through `glGet*`.
All the `glGet*` calls will first see if the attribute passed in is an attribute recognized by `glEnableClientState`
and if so, will retrieve that from `GL.immediate.enabledClientAttributes`.
Otherwise, it will call into WebGL for the value of the attribute.
Modified test included.
Added some SDL_Mixer calls:
- `Mix_Playing`
- `Mix_Pause`
- `Mix_Pause`
- `Mix_Resume`
Changed formatting and fixed a bug in response to Kripken's
recommendations.
Merge branch 'support-querying-client-state' into incoming
Merge branch 'sdl-audio' into incoming