Made VS2012 build the D3D11 renderer

This change is currently limited to Win32/Windows-Desktop builds.  Build fixes
for WinRT + VS2012 are still pending.

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extra : rebase_source : 1ba34b2a9a394347f5d95730eeabc3f0d7e4f197
Fixed compiler errors in the D3D11 renderer when building for WinRT

Still TODO: fix other build errors, especially linker errors, when building
SDL/WinRT, then fix any runtime errors that pop up.

--HG--
extra : rebase_source : dec261a0a61ffe463455f7d0a639f4c087e975ba