cekees/add cgal python

Added  the CGAL python bindings. The cmake-based  install is a little strange, but this is  working for me. @johannesring these might be useful for fenics. I'm guessing CGAL is mainly useful from C++, but I'm exploring the python bindings.
I'm happy to try this another way, but I'm not seeing how to do it. The core issue is that that the cgal bindings provide neither a  cmake style "install" stage nor a distutils style install stage AND the bindings need both because the bindings include both libraries that should eventually be located in PROFILE/lib and PROFILE/lib/pythonX.Y/site-packages.  So that way I designed this package file is to do the build the way the cgal guys designed  it, then to install and do profile_links the way hashdist  expects them.