Add DX11 Renderer

* Using WIC and some DirectXTK code for loading fonts and textures.
* Text drawing not working yet.
Fixed bug where Windows cannot to moved.

Fixed bug where Windows cannot to moved.

Only call SetCapture() and ReleaseCapture() when InputMouseButton() returns true.
Merge branch 'master' of https://github.com/topblast/GWEN
Merged pull request #87
Merged pull request #81
Merged pull request #82
Merged pull request #83
Merged pull request #84
Merged topblast/master