Augurer tweaks and a ranger tweak

The following changes originated with proposals from The Symposium:

Augurers now have two handed weapons at 95%. The cost for spiral blast has lowered to 15 mana. Prophetic aura will now provide a 50% resistance to blindness. Nostrum will cost half the mana and have lag similar to a potion quaff. The original proposal asked for a lower mana cost, but CoE felt it was too low.

For rangers, ursine brawn will also now add one damroll.