fix #H4275 - blinded, stunned, confused timers

Blindness due to face covered by pie was ignored for several cases
of magically curing blindness--cleaning the face seems better than
adjusting timeout to account for u.ucreamed for those cases.  A few
instances of taking stun or confusion damage overrode existing stun
or confusion rather than increasing it.  Plus a copy/paste mistake
for dual stun+confusion when casting an expired spell.

There was also a suggestion that vomiting when already nauseated
should decrement the timer instead of increasing it.  But there is a
negative effect for as long as it's in effect, so I left that as is.

doc/fixes36.1

@@ -185,6 +185,9 @@ wand/spell/breath zaps that reached the edge of the level on the Plane of Air
 stop amulets and other items which aren't affected by erosion damage from
 	being subjected to erosion damage
 grammar bit: polyself w/ gender change yielded "you turn into a Elvenking"
+some blindness cures ignored u.ucreamed
+some instances of stun or confusion timers were being overridden rather than
+	incremented when new stun or confusion damage was suffered
 
 
 Platform- and/or Interface-Specific Fixes