Avoid using killer_buf where it isn't needed

The use of killer_buf in contexts where done() can only be called in the
same stack frame as the cause of death interfered with its use as a
buffer for the cause of delayed deaths, currently only delayed
petrification from eating a cockatrice egg.
Deinstapetrify: delayed petrification when tinning petrifying corpses

Tinning a corpse that petrifies on contact without some sort of
protection will cause delayed petrification instead of instapetrifying
the player.
Deinstapetrify: delayed petrification when whip-snatching corpses

Applying a bullwhip at a monster wielding a cockatrice corpse and
yanking it into the player's hands will start delayed petrification and
drop the corpse instead of instapetrifying the player.
Deinstrpetrify: delayed petrify when removing gloves wielding corpse

Taking off gloves while wielding a cockatrice corpse starts delayed
petrification instead of instapetrifying.

Bonus: Taking off gloves while wielding a cockatrice corpse and being
petrify-resistant does not unwield the corpse.
Losing chromatic dragon armor while wielding petrifying corpse petrifies

Wielding a cockatrice corpse bare-handed while wearing chromatic dragon
scales/scale mail and then taking off the scales/scale mail now causes
petrification instead of just letting you continue to wield the corpse
bare-handed.
Deinstapetrify: delayed petrify when throwing corpse bare-handed

Throwing a cockatrice corpse while bare-handed now starts delayed
petrification instead of instapetrifying.
Deinstapetrify: delayed petrify when feeling cockatrice corpses

Feeling a location with a cockatrice corpse while blind or sacrificing a
cockatrice without gloves will start delayed petrification instead of
instapetrifying.

The first attempt of the relevant action will be interrupted if contact
causes delayed petrification or polymorphs the player into a stone
golem, but further attempts will work as normal.  This allows a blind
adventurer that feels a cockatrice corpse in an item pile to pick up a
lizard corpse in that same pile, or retry sacrificing a cocktrice
corpse to reduce prayer timeout.
Make wizard mode save bones prompt less annoying

It can be dismissed by pressing space to give the default answer of 'n',
and pressing 'q' at any of the end-of-game prompts skips it entirely.

I've worked on this for three years and I don't think I've ever used the
wizmode bones-saving feature even once.
Show end-of-game summary/tombstone even if skipping rest of disclosure

The tombstone in particular shows the cause of death, which is a lot
more interesting than most of the disclose stats, so I was often
disappointed when I skipped the usual disclose info but couldn't see
what the game think got my character killed.
Deinstapetrify: delayed petrify when bare-handed picking up corpse

Picking up a cockatrice corpse bare-handed now starts delayed
petrification instead of instapetrifying.

If picking up the corpse would cause petrification, it will be released
without adding it to the player's inventory.
Deinstapetrify: delayed petrify when touching corpse for container

Putting in or taking out a cockatrice corpse from a container will start
delayed petrification instead of instapetrifying.

The corpse cannot be put in or taken out without gloves or petrification
resistance.
Deinstapetrify: delayed petrify if polymorphed while riding cockatrice

Riding on a cockatrice with petrify resistance and losing it by being
polymorphed starts delayed petrification instead of instapetrifying.

Note: It's impossible to saddle a cockatrice or chickatrice (the only
monsters in the game that petrify on touch) anyway since they're too
small, let alone ride them, so this case will never be encountered in
gameplay.
Deinstapetrify: delayed petrify when saddling petrifying monster

Attempting to saddle a cockatrice without gloves starts delayed
petrification instead of instapetrifying.

Unlike the last commit, even though neither cockatrices nor chickatrices
can be successfully saddled, the attempt to saddle them will still be
made and thus may trigger this case.
Deinstapetrify: delayed petrify when mounting a petrifying monster

Attempting to #ride a cockatrice without petrify resistance starts
delayed petrification instead of instapetrifying.

Note: For this case to trigger the cockatrice/chickatrice must first be
saddled, and since the game never allows them to be saddled, this case
will never occur in gameplay.
Deinstapetrify: delayed petrify wielding corpse and falling/unprotected

The following cases where a cockatrice corpse is wielded now start
delayed petrification instead of instapetrifying:

 * falling downstairs due to burden or attached ball and chain
 * falling down a hole or trapdoor
 * falling onto a sink when levitating over it
 * falling into a (spiked) pit

And for when a cockatrice corpse is wielded bare-handed and petrify
resistance is lost:

 * taking off chromatic dragon armor
 * polymorphing into another form or your original form

In these latter cases, the cockatrice corpse is released.
Deinstapetrify: delayed petrify when untrapping cockatrice bare-handed

Using the #untrap command to help a cockatrice in a trap while
bare-handed starts delayed petrification instead of instapetrifying.
Deinstapetrify: delayed petrify stealing cockatrice corpse bare-handed

Stealing a cockatrice corpse from a monster while bare-handed starts
delayed petrification instead of instapetrifying.
Deinstapetrify: delayed petrify when engulfing cockatrice

Successfully attacking a cockatrice with an engulfing attack starts
delayed petrification instead of instapetrifying.

Bonus bug fix: Biting a cockatrice and surviving its petrification will
no longer instadisintegrate you.
Prevent random chance of same-race polymorph with wizmode #youpoly

This removes the 1-in-5 chance to have level/attributes shuffled instead
of getting the polymorph form you asked for in debug mode.

Seriously, this omission getting me killed in wizmode was driving me up
the wall when testing changes that required me to be in the form of
other monsters, like the last couple of commits.
Deinstapetrify: delayed petrify wielding cockatrice corpse bare-handed

Wielding a cockatrice corpse while bare-handed starts delayed
petrification instead of instapetrifying.

Bonus fix: If doing this turns you into a stone golem, the wield
proceeds as usual.