Allows PEs to improve passively.

This gives most PEs a chance to increase when they are actually helping the player, instead of on cast only. You simply need to have cast the PE on yourself (other player's buffs don't count) and it will have a chance to improve when it's working for you.

Offensive PEs (Bless, SS, Kara) get an improvement check about once every 50 attacks the player makes.
Defensive PEs(Gort, MS, Invis, shadowform) get an improvement check about once every 5 kills, provided the player was swung at by the mob.
Resistances (all elemental resistances and RM) get an improvement check about once every 10 times the players takes the appropriate elemental damage.
FA and EE get an improvement check about every third time a hold/blind/dazzle is cast on the player.
Resist Poison gets an improvement check every time the player is poisoned or resists a poison.
Deflect gets an improvement check about once every three times a player is attacked with an attack spell.
Cloak gets an improvement check about every second time someone seances him, provided the seance hasn't locked on the wrong room yet.

These rates won't keep people from botting just yet, but we have to start somewhere and see where it goes and how it feels.

Also, quite a few spells are still left out in the open: Detect Invis/Evil/Good, Haste, Nightvision etc. We will have to think about decent ways to allow these to imp.