Added cmake

CMakeLists.txt is usually placed in the root folder, this is a basic
cmake file that will do everything nessesary to build the program as
either as a library of another program or by itself.
Merge pull request #26 from Rod-Persky/cmake

Added cmake. Thank you for the contribution. We thought about CMake for a while, but I never got it to work properly. I am sure there will be some more questions very soon, but I'll merge it for now. Thanks again!