D3D: Use two slices for most of our textures.
D3D: Add GeometryShaderCache.
D3D: Add geometry shader stereoscopy support.
D3D: Add SBS/TAB output support.
D3D: Add 3D vision support.
D3D: Restore viewport after stereo blitting.
D3D: Use common GetEFBLayers() instead of GetEFBSlices().
D3DTexture: Bind textures as texture arrays.
D3D: Add geometry shader instancing support.
D3D: Set the geometry shader for triangle primitives.
PixelShaderGen: Sample the correct texture slice.
D3D: Recreate the framebuffer when stereoscopic 3D is toggled.
PixelShaderCache: Add texture array support to static shaders.
PSTextureEncoder: Add texture array support.

We only read the first slice, because EFB2RAM doesn't support texture arrays.
D3DUtil: Use a geometry shader to clear all slices.
TextureCache: Add stereoscopy support for EFB to texture copies.
D3D: Add anaglyph stereoscopy support.
Cosmetics
PixelShaderCache: Fix MSAA shaders.

Various typos were introduced due to lack of testing.
Cosmetics