Added the 'SimulationDelta' type to facilitate event firing on simulation, updated the 'State' type to utilize this new type, and added tests for this type.
Updated the names of all the testing classes so that they correspond with the names of the module.
Added full unit testing for the 'State' class and added an equality operation to the 'SimulationDelta' type.
Updated the tests for the other state types based on the changes made to the 'State' class.
Updated the 'StateMachine' class and its associated tests to integrate the 'State' and 'Transition' classes.
Finalized the interface for the 'Entity' class after many hours of toiling.
Updated the 'State' and 'StateMachine' tests to incorporate an abstracted 'TestState' type to improve testing coverage.
Added full testing for the 'Entity' type using the newly refactored testing 'State' derivatives and 'Entity' derivatives.
Task 0.5 complete. Added UML generation

UML generation is accomplished with pyreverse, which depends on graphviz
(both have been added to .requirements.txt). To facilitate editing the
diagram, we convert the .dot file that pyreverse produces into a
.graphml file. The resulting .graphml file can be edited in a program
called yEd (http://www.yworks.com/en/products_yed_about.html), which
has cross-platform support and works quite well.

(Note: We can output the class diagram as any other image type but we
cannot easily edit the resulting file).
Parameterized output type for the `uml` target.

By default, the `make uml` rule now outputs a .dot file, which is
automatically converted to a .graphml file. This can be overridden by
setting the `UML_IMG_TYPE` variable when calling `make uml`. For
example, if you wanted to save the diagrams as PNG files then you would
run

    `make UML_IMG_TYPE=png uml`
Changed parameter name.

Simplified paramter name from `UML_IMG_TYPE` to `IMG_TYPE` since the uml
part is implied by the rule.
Integrated the 'HashableRect' type into the 'PhysicalState' type to support collision detection.
Merge branch 'Task-7.4' of github.com:NintenJoe/zol