Add device, adapter, output, and mode querying.

[mtwilliams]

For Direct3D9, this means using the IDirect3D9 interface.

For Direct3D11, this means using IDXGIFactory::EnumAdapters and IDXGIAdapter::EnumOutputs and IDXGIOutput::GetDisplayModeList.

For OpenGL 2.1+ and OpenGL 3.1+, this means using EnumDisplayDevices and EnumDisplaySettings on Windows, and God knows what on other platforms. Vendor-specific extensions have to be used as well, namely WGL_NV_swap_group, WGL_NV_gpu_affinity, and WGL_AMD_gpu_association.

For OpenGL ES 2 and OpenGL ES 3 this isn't much of an issue, however there might be a brute-force method via eglGetDisplay.

[mtwilliams]

This has been implemented for Direct3D9. It still needs to be debugged and cleaned up.