Monster mana and spellcasting infrastructure changes, Mana Bomb changes (against mobs), new message for ranged mob chance-to-attack.

Design document: http://wiki.openmeridian.org/index.php/Monster_Mana_and_Spellcasting_Infrastructure_Changes
Forum thread:http://openmeridian.org/forums/index.php/topic,270.0.html

Added monster spellbooks; these are a list of spells the monster can cast with their cost and chance-to-cast (used by monster.kod when it checks which spell to cast using random(1,100)). Moved monster spellcasting code to monster.kod so any monster can have the plSpellBook and cast spells from it.

Moved mana handling from Player and various Monsters to Battler. Monsters can now have their mana altered by the same mechanisms as players, e.g. the new implementation of mana bomb.

Changed Mana Bomb's effect on monsters to be the same as it is against players. Mana bombs done by a player will generally take all of a monster's mana, stopping it from casting spells for a short period. Players will now get a message when they cast or are the victim of a mana bomb, telling them how much mana was taken away.

Added a new RangedAttackChance for ranged mobs to use instead of the AdjustedChanceBase which spells use; now checks Vertigo, Winds and Sandstorm for ranged attacks instead of spell-specific counters (AmA, Dement).

Xeos will now gain the mana they drain from players, acting as sort of a mana steal. Mana bombing a xeo will serve the dual purpose of taking all their mana, and preventing them from getting yours.