These scenarios can happen when a GPU is switched, its driver updated, or in
some virtual machines (such as Parallels) are suspended and then resumed. In
these cases, all GPU resources will already be lost, and it's up to the app to
recover.
For now, SDL's D3D11 renderer will handle this by freeing all GPU resources,
including all textures, and then sending a SDL_RENDER_TARGETS_RESET event.
It's currently up to an app to intercept this event, destroy all of its
textures, then recreate them from scratch.
This changeset prevents IDXGISwapChain::ResizeBuffers from being invoked on
Windows Phone 8, a function that isn't available on the platform (but is
available on other Windows platforms). The call would fail, which ultimately
led to a crash.
This changeset also attempts to make sure that the D3D11 swap chain is created
at the correct size, when using Windows Phone 8.
Still TODO: make sure rotation-querying works across relevant Windows
platforms (that support Direct3D 11.x).
The D3D11 renderer is now slightly faster than D3D9 on my Windows 8 machine (testsprite2 runs at 3400 FPS vs 3100 FPS)
This will need tweaking to fix the Windows RT build.
