[svn] Implemented player on player and player on creature possession:

* Implemented packet and vision forwarding through possessed units
* Added new OnPossess script call alerting scripts on when possession is applied/removed
* Moved fall damage and fall under map calculations into the Player class
* Added new PossessedAI that is applied only while possession on creature is active
* Implemented summon possessed spell effect
* Fixed Eyes of the Beast

--HG--
branch : trunk

sql/updates/182_world.sql

@@ -0,0 +1,4 @@
+DELETE FROM `command` WHERE name IN ('possess', 'unpossess');
+INSERT INTO `command` (name,security,help) VALUES
+('possess',3,'Syntax: .possess\r\n\r\nPossesses indefinitely the selected creature.'),
+('unpossess',3,'Syntax: .unpossess\r\n\r\nIf you are possessed, unpossesses yourself; otherwise unpossesses current possessed target.');