New Throne Room

This includes a change to Castle Victoria's Throne Room, and a new
Throne Room area beyond it.

The Ghost no longer spawns in Throne Room 1, as this was interfering
with players building up to 100 hps.

The Ghost now spawns in Throne Room 2 by itself, so that low-level
builders aren't interfering with high-level builders.

The Ghost also had its loot profile upgraded, and its one-item-per-kill
restriction lifted. Ghosts now have a chance to drop hold weapons. As a
balancing mechanism, throne Room 2 prevents the casting of wall spells.

This should help mid-level builders fight in throne room without having
to fight the ghost, and also allow high-level builders another option for 150.