Major restructuring of application.

This was a major refactoring of the code.  I removed a bunch of
miscellaneous files and pared BondegaTwit.py down to only a few lines.
The Markov class was changed to MarkovTupleGenerator.py, which is the
original class.  It is now in it's original state.  I removed all of
our code that was added as methods to the Markov class and wrote a
new class, MarkovGen, that extends MarkovTupleGenerator.  It's a lot
cleaner.  Global variables have been pulled into the BondegaTwitConfig
file.