Added a way to test freeze.

Not sure why, but it only works on one unit at a time. Assumptively
because the spells have default cast points, and the first gets canceled
when the second was is cast.
Edited skills around for testing
Added Frozen Buff, and an upgrade

Frozen buff is the spell that freezes units, needs to be hooked up to a
hidden unit?

Frozen buff 2 is a planned upgrade that will slow units within a certain
area of a frozen player.