Fixed some "Entity was not found in any chunk!" warnings

Player's current world is saved in the player file. When a player joins the server, the player joins the last world he was in.
It seems MCServer can finally run multiple worlds! It just needs functionality to switch between them

git-svn-id: http://mc-server.googlecode.com/svn/trunk@46 0a769ca7-a7f5-676a-18bf-c427514a06d6

source/cWorld.cpp

@@ -88,6 +88,7 @@ cWorld::~cWorld()
 	{
 		cEntity* Entity = *m_pState->m_AllEntities.begin();
 		m_pState->m_AllEntities.remove( Entity );
+		if( !Entity->IsDestroyed() ) Entity->Destroy();
 		RemoveEntity( Entity );
 	}
 	UnlockEntities();