Completed implementation of monster classes and factions in the monster resource...

Completed implementation of monster classes and factions in the monster resource file, so that these properties are read from there.

Also introduced a property of uniqueness per monster (meaning that unique monsters will not respawn). This will replace the uniqueness that was previously set on spawn areas, since it is more intuitive to define it per monster type.

git-svn-id: https://andors-trail.googlecode.com/svn/trunk@215 08aca716-68be-ccc6-4d58-36f5abd142ac