CS158: Prevent accidental cancelling of a wish

Compared to the UnNetHack change, this commit also removes a redundant
check for escape afterwards.
CS159: Allow alternate spelling for mind flayer

This also stops monks accidentally genociding themselves when they type
'master mindflayer' (without the second space), which would otherwise
just match 'master' (a monk title).
CS160: Burn level-specific random engravings

Also adjust the try-limit code I added.
CS161: Make quest nemesis ignore Elbereth

They're intelligent beings, so some writing on the floor shouldn't faze
them.
CS162: Partial Polysink patch by L and Paxed

This changes some effects and messages for dropping rings down sinks.

Dropping a ring of teleportation will teleport the sink. ("The sink
vanishes!")

Dropping a ring of polymorph will polymorph the sink into a fountain,
throne, altar or grave. ("The sink transforms into a fountain!")

Dropping a ring of polymorph control marks the sink as unlooted. ("The
sink transforms into another sink!")

Dropping a ring of warning now says, "The sink glows red for a moment."

Dropping rings of aggravate monster, meat and see invisible give
slightly different messages when hallucinating.
CS163: labelread patch (by L)

Original patch: http://bilious.alt.org/?202

Allows the following non-scroll objects to be read:

 * gold pieces
 * tins
 * cans of grease
 * candy bars
 * credit cards
 * magic markers
 * the Orb of Fate
 * runeswords, runed broadswords and daggers

Most of these won't be listed in the read prompt, but you can still
choose them with their inventory letters. Tins, cans of grease and candy
bars have no labels, but all the others give flavor messages. Try being
an elf or archaeologist for different messages for the last items in
that list.

UnNetHack does not include the coin flipping patch that the original
patch rolls in, so it's not here either.
CS164: Make fighting noisy (SporkHack)

This stops players from killing entire rooms full of sleeping monsters
while they're asleep.

How it works:

 * Darts, shuriken, knives and 1 in 3 fired missiles are silent.
 * Knife attacks with stealthy characters are silent.
 * Stealth greatly reduces the noise of combat.
 * Non-weapons, Mjollnir and bullwhips are always noisy.
 * Monsters in range have an 80% to wake up, 66% if a rogue.
CS166,175: Split pudding 1/2 MaxHP; no death drops

This prevents the dubious practice of pudding farming for the most part.

However, it may still be possible with a ring of conflict, since
monsters gain max hit point from killing other monsters, but it's still
much harder than before.
CS167: Choice of Sokoban prize (NetHack Brass)

Sokoban now has a guaranteed prize again! Three to be exact:

 * bag of holding
 * cloak of magic resistance / displacement
 * amulet of life saving / ESP / reflection

Picking up a prize makes the others vanish. You can only full identify
the prizes when they're in sight. The prizes will never be picked up by
monsters or fall down holes before you have a chance to get to them.

Compared to the UnNetHack changeset, I renamed a couple of variables
named "price" that were clearly meant to be "prize", and renamed
"del_sokoprize" to "del_sokoprizes" to better reflect intent. I also
rearranged the del_sokoprizes code a bit to account for buried Sokoban
prizes making popping noises.