Major changes so that deltaTime is taken into account

- changes so that everything is updating based on deltaTime (including
  rate of fire, fuel, movement, and lifetime)
- added deltaTime to Game class so collisions could access it
- fixed collision handling so that it takes deltaTime into consideration
- removed indicator class as it was redundant with ObjectiveIndicator
  class
- added lifetime variable to missiles
- updated TODO
- added documentedBugs.txt as a place to list defects separate from TODO