#6 Make Python module of FDNT

The Python interface is working, and I need to wrap up this issue.  This pull request is to remind myself what has been done.

Major changes:
 * scons compilation (easy to deal with compiler differences of different systems)
 * Python / C++ interface with Boost Python
 * A sample Python script: examples/demo1.py 
Seems like this line should be `default_cxx = 'g++'`, given its usage.