Fixes Python interface to bots::user

Except for the bots::user::active wrapper, the interface class worked
perfectly, once the infinite hang on import was fixed. That method
wrapper is now fixed
Documents Makefile, minor bugfixes

Since I was experimenting with four different interfaces between C++ and
Python (SWIG, boost::python, the Python C API, and Cython), the Makefile
was undergoing constant changes; now that I've settled on Cython, I went
through and documented the various parts of the Makefile, and the config
file (config.mk).
Modifies Python package structure

Since the bots directory is already a subdirectory of the main Django
app directory, instead of having to import the interface extension from
bots/lib, I edited the Makefile to symlink extension libraries to the
top-level bots directory
Adds historical exchange data

In order to enable testing with historical data, we will, at some point,
need that data; I fetched all of the data available in USD from
bitcoincharts.com, which is current as of 2/7/14 (at the earliest)