Added PDFToImage pdf-image converter method.
Added test image made by PDFBox.
Moved PDFBox parsing for angle list to PDFToText (it makes more sense for it to be there).
Commented out some lines in AirportController that were making testing the image writer difficult.
Added traverseLeft, traverseRight, and traverseBottom (tentative based on documentation).
Added tentative documentation.
Added isBlack function to Point class.  It takes a BufferedImage to use to determine the point's color.