Enabled disposing of the user interface.

UI testing needs a UI that can be disposed programmatically.
Ensured sprites are loaded at most once from file

This speeds up loading games substantially.
This reduces test time for end-to-end tests loading full maps.
bin target added by eclipse in git ignore
Added end-to-end smoke test

This also serves as an example how testing
with user interface code can be conducted.
JPacMan User Stories

Following the behavior-driven development format.
Merge pull request #7 from avandeursen/ui-testing

Changes to facilitate UI-level testing and improved the sprite store.