This started out as a change to address the strange sequence of messages if
you remove a blindfold while engulfed in a dust vortex. That is addressed
by a new function that can be called in such situations. Calls to this
function were added in all the cases where the can_blnd() engulfing
conditions end as a result of player action. There are some other cases
that end ucreamed or usleep, but they happen between turns and shouldn't
need extra handling.
While I was at it, I noticed that a unicorn horn or prayer would cure
blindness even while engulfed in a dust vortex. This is useless, because
you immediately get blind again the next turn. So, I added checks to avoid
doing this. Finally, it didn't make sense for eating a carrot to cure your
blindness in these situations either, only for it to return immediately.
345ffcfaec