started histparse.py (incomplete)

histparse.py is the module to handle reading in history files and
creating graphs to be used by visualizer. actual graphmaking
is currently incomplete, and only Firefox history files have any
support. Chromium/Chrome will be added next, then graph creation.
history extraction and graph creation done...?

I think that the code for pulling data from the history file and
putting it into a graph is finished, and my tests come out OK,
but more rigorous testing might be good. Currently, only Firefox
is supported, and I think Chromium is the only other one we can
add to that (IE is a binary blob, Safari uses plist (?)).
Chrome query needs more testing but think it works
bug in Chromium query fixed, think module is good for now