Implemented arrow shooting in Wumpus World. Wumpus Environment is now complete.

Fixed bug where dead agents still get to act (Environment)
Improved Direction class to ease 2D Movements (Direction)
Implemented an easier way to iterate with and without walls (XYEnvironment)
Added is_inbounds() method to check if location is within the width and height. Works within walls also. (XYEnvironment)
Multiple Minor Fixes(agents.py)

WumpusEnvironment

- Fix relative imports in base of is a package or not
- Fix not working notebooks
- Add notebooks to packages sources

Used tool 2to3 to finish the porting to Python 3 plus some fixes by
hand.

Will add some kind of GUI later -- but this one didn't do much.

modified print statements in agents.py to make it work in Py3, changed utils_test.py with regard to new utils.py

use “raise NotImplementedError” for abstract methods

Agent.__init__ now takes a program parameter. A few more nonlocal-state-variable problems found and fixed. One agent program rewritten as a callable instance since it uses both state variables and abstract methods.

Moved agent-program definition back into the constructors to get rid of all the copying between parameters, instance vars, and nonlocals. Fixed nonlocal state-var bug in ReflexAgentWithState.

XYEnvironment.  Identified three possible inelegances or errors in the 
__init__ method of EnvCanvas.

Changed 'Delay' slider to 'Speed' slider;

Changed self.running values to boolean True, False.

for more uniform initialization of Agents.

Improved GUI with commands to list objects and agents.

Fixed GUI speed control (delay slider), narrowed the
range and increased the resolution.

Added three new image files and image credits file.
Better image for dirt

EnvCanvas draws each object either as a canvas text (string) or using
an image from a file associated with the object class.

Implemented delete_object for Environment and XYEnvironment,
renamed XYEnvironment methods objects_at and find_at as
list_objects_at and some_objects_at, for clarity;
revised arguments lists of list_objects_at and some_objects_at;
revised implementation of bumping to work with new list_objects_at and
some_objects_at.

Promoted XYEnvironment methods list_objects_at and
some_objects_at to Environment.

Defined can_grab method for Agent class,
replacing Object method is_grabable.

Cleaned up code, removed tracing print statements, etc.

Removed -1 penalty for Nop in VacuumEnvironment.

Added Tk mainloop to test_gui, and commented out call to test_gui.