added a linear backoff for repeated use the same move.
(intendid an exponential backoff but swayed away from that decision)
If a creature uses the same move more than once,
it is less effective (some kind of fatigue per se).
I changed the AI to account for this backoff, so that
the creature knows not to use the same move multiple times.

In addition, then end of a battle modifies a creature's experience
and level, if necessary.

I also gave an example of how a function is supposed to be written
to start a BattleActivity with any given Battle. (commented explanation)

Also, some minor bug fixes.
Made some more final changes
Merge branch 'master' of https://github.com/mtabor150/CampusCreatures into feature_ExponentialBackoffForRepeatedActions
Merge pull request #47 from pmarti28/feature_ExponentialBackoffForRepeatedActions

Feature linear backoff for repeated actions