Changes:
- Removed dependency on D3DX libs and dxerr lib:
      -- Removed libs:
             d3dx11d.lib
             d3dx9d.lib
             d3dx11.lib
             d3dx9.lib
             dxerr.lib
      -- Removed headers from all the  .h and .cpp files
             DxErr.h
             D3Dx11.h
             D3DX10math.h
             d3dx9math.h
             D3DX11tex.h
      -- Replaced DXGetErrorString(...) with FormatMessage(...)
D3DX API is deprecated this is prerequisite step to drop standalone DirectX SDK and move to Windows SDK.

- Removed unused xnamath.h header