EnemyControllerr Added

No change in end user functionality, but EnemyController is a thing to
be modified now.
EnemyController and Tornado

EnemyController is mostly done. Tornadoes are now random heights, up to
80% of canvas height.
EnemcyController Finished

EnemyController is finished for the most part and difficulty increases
every 1000 points, it get's pretty hard at 5000 which seems to be about
the right pace.