Don't place zombified monsters using PROX_NEAR_STAIRS.

Mention the incapability of leaving levels in the descriptions of zombified monsters, and also for Animate Dead/Skeleton.

git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@7993 c06c8d41-db1a-0410-9941-cceddc491573

Created by  j-p-e-g  on December 27, 2008
UW2ZVPHGKMKJVTB5LIV2DZCHXY6DSFRZ6DMKHLHFNHZUPRUAKHUAC
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