build: Microsoft Visual Studio compilation support

[JanSimek]

I fixed the Windows build with MSVC. Unfortunately, I am at a loss on how to make a proper pull request which contains only these two commits and not the whole fork:

JanSimek@5c54572
JanSimek@0ce6c72

I haven't done any playtesting yet, but it compiles fine on Windows 7 and OS X 10.9

[vayerx]

If there are one or two commits, I can cherry-pick them manually. But if you would like to make a pull request, you should create a new branch from the latest fetched commit in target branch of my repository and cherry-pick necessary commits to that branch. Then you'll be able to create pull request.

[vayerx]

I've merged those commits. Thanks for patches!
I made small changes in data-paths logic -- please could you check if it works for Windows.

[JanSimek]

It's a little bit inconvenient, because this way you have to specify these data path variables on the command line and you can't use cmake-gui, because those variables are not set. Most people use cmake-gui to configure CMake-based projects.