tracking.py fixes and environment changes

gistfile1.sh

#For OS X:

# Install homebrew (http://brew.sh/) with this command:
ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

# Then install opencv:
brew update
brew upgrade
brew install liblo

# Close your terminal session and open a new terminal window. Then do this:
echo "export PYTHONPATH='/usr/local/lib/python2.7/site-packages'" >> ~/.profile
source ~/.profile
sudo easy_install pip
sudo pip install pyliblo

brew install homebrew/science/opencv

# Now this should work if you are in the tutorial_tracking directory
python tracking.py glasses.txt