Feature/build system

Improve the build system:

 - Move c++/cython extensions in a lib folder
 - Keep pure python code in a regular pyludic package
 - Cleaner root tree
 - The compiled c++/cython extensions are copied back into the regular pyludic package
 - Keep the ability to replicate pure python source tree when building with cmake (for deb packages)
 - Build with Visual Studio 2010 on Windows (the recommended compiler when building python3 extensions)