Fix libs depot, add TOOLS switch in CMake for building tools support int...

I wanted to add back the tools support that was there in the original doom3.sln. I added a new TOOLS switch in CMake which will build the tools into doom3.exe if you're on MSVC. It's OFF by default so people with the Express edition can still build. I had to fix a couple of issues where some headers for MFC where moved from the original GPL code and it didn't build properly.

I also fixed the libs depot URL that was in the README because it was renamed.