Added trapdoor spider (not yet randomly generated). If a trapdoor

spider can't see any enemies and is on a floor square it will "submurge" into the floor and only come out if an enemy moves right next to it or if something attacks it from a distance. Most of this is done with the new monster behavour BEH_LURK.

git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@5477 c06c8d41-db1a-0410-9941-cceddc491573

Created by  zelgadis  on June 4, 2008
3HGELZU7NELOQ635HZO6IJIYLBSNCJ5VPH46IE22KA3OSLEFK7AQC
Change contents