#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 
'g++' is everywhere in this file---should this line at least be replaced by the variable `default_cxx`?
Or should `default_cxx` be replaced by 'g++'?
This is probably a question that should be addressed to @rmjarvis.