Added FOV distortion model. This model is based on fisheye field-of-view
distortion as seen in
http://hal.inria.fr/docs/00/26/72/47/PDF/distcalib.pdf

The FOV model attempts to load superframes with .pgm extensions in
/calibration/pgms/, remove distortion, and perform marker detection.
Currently it only works on pre-saved pgm images. The pinhole model
currently only works on the live camera feed. Also refactored code
throughout project.