Unaware; fix #H202 and extend the fix for #H179 (trunk only)

Unaware; fix #H202 and extend the fix for #H179 (trunk only)

     Turn being unconscious (via several reasons, including fainted from
hunger) into a pseudo-property named `Unaware' and use it in several
places where only being asleep was checked.  #H202 was about a stunned
character who got the recovery message when it timed out while fainted.
This suppresses messages for several difficulties when they begin or end
while hero is Unaware.  Messages about fatal illness, sliming, or
petrification aren't suppressed; they're too important to hide from the
player.  "You feel ..." messages come out as "You dream that you feel ..."
when Unaware; fairly lame but hopefully adequate.