Add support for Actum crit modifier

[andrewbelu]

With two actum's equipped (one 20% crit, one 30% crit):

[PJacek]

This is incorrect. You changed the base crit chance of the weapon.

[andrewbelu]

This is incorrect. You changed the base crit chance of the weapon.

Ah, misread the mod, I thought it was base crit but as you mention looks to be the exact crit (who would use this axe lol). Will fix

[Wires77]

This wouldn't work against the old assassin's mark, which specified "Enemies have x% chance to be crit", but since they changed that wording and I don't know of anywhere else that was worded that way, this looks good to me.