More flexible combat masteries.

Training Talents can have the following fields:
- getMasteryPriority(self, t, kind) - Only the talent with the highest is used. Defaults to the talent level.
- getDamage(self, t, kind) - Extra physical power granted. Defaults to level * 10.
- getPercentInc(self, t, kind) - Percentage increase to damage overall. Defaults to sqrt(level / 5) / 2.

Should be compatible with all existing masteries.