Started support for level 3.

- Added Level03, an IPowerSource that uses the selected origin's utility
  power.
- Added UtilityPower propert to origin. The check for setting it is
  currently commented out in AddModifiers.
- Added utility power for the Android origin, "Be My Battery".
- Added test level 3 character (clip).
- Updated CharacterTest.TestUtilityPower to check the effect. Updated the
  existing character tests to test the effect, too.
Added three more utility powers and tests for each.

- Added ScoreBonus to represent the sum of character scores.

Future work:

- Add scores for ability modifiers then redo bonus framework. Weapon
  accuracy bonuses may be an issue but can be supplied separately.