Clean up some of the data structure files a bit.
wtfwhitespace
Pull out the combat unit concept into its own explicit class, and use that to simplify battle setup.

Also extend test case to include effect removal.
NOTE the test cases pass, but I haven't thoroughly audited to make sure this didn't break anything.
The combat unit interface is up for debate as well. (My only concrete plan is that it will have
helper methods for movement.)