fixed makefile bug
oops forgot to add this file
added boykov and kolmogorov maxflow code (not ours)
added cython C++ extension for boykov and kolmogorov max flow algo.

There are 6-10 ways of calling native code from python.  Cython seems
the easiest and most advanced.  Cython is its own language, and is
"almost python" but understands C types too.

So far just 2-label inference.

At the moment you have to build it like this:

> cd maxflow
> python setup.py build_ext --inplace
Changed sceneLabel2.py example to use ultraflow library.

ultraflow is in the ./maxflow subdir, it's our interface to the B&K
code, replacing PyMaxflow.

When you run the demo you have to tell it where to find our module,
using the PYTHONPATH variable.  In bash you can use "export PYTHONPATH=..."
to set it permanently (or in your .bashrc), or on the command-line
when you run it like this:

> PYTHONPATH=./maxflow ./sceneLabel2.py
started a latex doc with some notes.

To view:

> pdflatex alienMarkovNetworks.tex
> evince alienMarkovNetworks.pdf