"Necropolis" - changes to creatures of levels 6-7.

SRD, by default, Necromancy raises units from the Necropolis army. I don't know if this can be changed, but it would be better to make it raise Skeletons, as it was, along with dragons. Dragons should be made into powerful 8th-level neutral creatures, with one having a death blow and the other having incorporeality.