Added potions of resistance, which give fire, electricity and cold resist for

10 + random2(40) turns. Rareness roughly equivalent to levitation. This is FR 1756363. The potion does not give MR. Rewrote some vampire potion handling, including some changes: e.g. vampires can now be paralysed by potions of paralysis (I don't see why they shouldn't be.) For now there is no status message for fire/cold resist; will change soon.

git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@1918 c06c8d41-db1a-0410-9941-cceddc491573

Created by  haranp  on July 23, 2007
JK3HFJG76OOQHJMXJUSZRTR5CX5ZMS52LRVBLOR7E2NBI6PRSHHAC
Change contents