Retreat while reloading Attribute

Currently, only anti_heavy units retreat while reloading.

It would be very useful to be able to apply this behavior to certain other units, which are not currently anti_heavy:

> Snipers
> Moderator
> Placeholder
> Dominatrix
> Dagger
> Scalpel
> Penetrator
> Kodachi
> Panther
> Catapult
