Added code to expose the persistence_diagram class, the bottleneck_distance function and the point class to python. Most of the commonly used methods for each class have been exported. The constructor for point now requires that a data argument be provided along with x and y coord. This needs to be made optional. The constructor for persistence_diagram could possibly be rewritten as well.

set                         (targets                        
                             cech-complex)
                             
foreach                     (t ${targets})
    add_executable          (${t} ${t}.cpp)
    target_link_libraries   (${t} ${libraries})
endforeach                  (t ${targets})