Have towers randomly scattershot when they can't deal enough damage on any target

[CarsonBurke]

Every random range 100 ticks or so have towers attack one enemy per tower to try to mess up the healing of enemies that should be able to out-heal enough damage. This might trip up attackers with imperfect healing ability, helping defenders get in extra damage and pushing enemies from ramparts.

In the future, the bot should consider how the enemy reacts to the scattershot and change defence strategy in response. Say, if scattershot fails a lot it should stop, If it works, it should continue more frequently.