Removing equality operator from BlendState. Updating tests accordingly.
Adding additional equality tests for BlendState.
Removing equality operator from DepthState. Updating tests accordingly.
Removing equality operator from RasterizerState. Updating tests accordingly.
Removing equality operator from Viewport. Updating tests accordingly. Rearranging mock libraries and adding one for GraphicsDeviceCapabilities. Adding equality tests for SamplerState.
Added an ArgumentError when passing a null device to the constructor of DeviceChild.
Adding checks for ArgumentError when constructing with a null GraphicsDevice.
Merge remote-tracking branch 'upstream/master' into compressed-textures
Merge pull request #36 from donny-dont/compressed-textures

Test cleanup