#6 Added start_turn_draw_card ability. Passive abilities on frozen cards are ignored
#7 Added the overheal ability and overheal action
#7 Added negative heal amount check to HealAction so that overheal will not cause the standard heal to actually damage the unit
#3 Added maxHealthBuff and damageBuff to hero and cards to support buff abilities
#3 added energy and energyBuff to card battle schema so that energy levels on cards can be modified
#10 Added modifier infrastructure and updated current abilities to utilize it
Merge pull request #11 from rswhiting/master

New cards
Merge pull request #2 from DougHamil/master

pull in more of Doug's code