Alphashapes and Python bindings
  * converted alphashapes2d to the new format
  * added Python bindings for alphashapes
  * added sample alphashapes.py that dynamically distinguishes between 2D and 3D
set                         (targets                        
                             cech-complex)
                             
foreach                     (t ${targets})
    add_executable          (${t} ${t}.cpp)
    target_link_libraries   (${t} ${libraries})
endforeach                  (t ${targets})