Adds a few reference images.
Adds more reference images
Fixes servo code and firmware, updates example
Fixes a typo in the servo example
Refactors arduino lib slightly, fixes stop function, adds timer example

The stop function originally simply killed the arduino commuincation
thread, but did not send a packet to stop motors to the arduino, so
the arduino was continuing to run motors at whatever speed they were
last run at. The communication thread now calls self.cleanup() before
quitting. This function sends a final packet to the arduino.

In order to do this, I refactored out the code for writing an
output packet and reading in an input packet into class functions.
Merge branch 'master' of git://github.com/gkanwar/maslab-staff-2013
Vision code detects red balls and draws the contours around them. I need
to pick a point within each contour as the "center" of a ball (so we can
turn towards it) and organize the code into functions so it will work
for green balls as well.

cvTest is the vision code. It filters the image based on hue and the
"distance" between a pixel's color and a preselected "red" color. It
finds contours and classifies sufficiently large contours as balls.

cvhueDisplay displays colors and prints their hue values when you click
on them.