Fixed renderer flags to include support for target textures after the renderer is created.
Converted David Ludwig's D3D11 renderer to C and optimized it.
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.

--HG--
rename : src/render/direct3d11/SDL_render_d3d11.cpp => src/render/direct3d11/SDL_render_d3d11.c