Added __init__.py to visualization folder.
Fixed heat_map() method, now prints all shapes. Shapes that can't be matched on title are colored grey. Added doc string. heat_map() can output plot in three different formats; in a stream, as a plot in a new window or saved in a file 'plot.png' in the current directory.
Updated index template. Added contents used by template.
Log traceback from unhandled exceptions.