CMake support

Hi,

I've added CMakeLists in order to simplify the compilation. The Makefiles in git were not up-to-date.
It's working on Linux and MacX but not yet on windows.
The README.md explain how to use it, and it seems CMake is able to generate CodeBlocks projects.
I'll have a look at the windows problem as soon as I'm able to debug in Visual Studio.

Morgan Leborgne (ZIB)