delete bug and landscape from root dir
add main.py
README: add example invocation, remove extra features, minor tweaks
formatting in bugbuster, fix unorderable types error discovered in win py3.4

It seems like in Windows Python 3.4 (probably in Linux 3.4 as well) int and NoneType can not be compared, hence x_max and y_max need to be initialized with 0 instead of None.