Don't waste potions of speed, flight or invis.

Invis can be drank while contaminated which isn't going to do anything good,
but it has a non-zero effect.
Remove double spaces.
Remove hardcoded ENDOFPACK from a message
String semantics
Replace `mprf(s)` with `mpr(s)`

Scripted, then manually reviewed.
Replace `mprf(ch, s)` with `mpr(s, ch)`

Scripted, then manually reviewed.
Rename mprnojoin to mpr_nojoin

For consistency with mpr_nocap, mpr_comma_separated_list and friends.
Can "You die..." message
Orient linesprint horizontally only.

On most console and many tiled displays, there is more map room
horizontally, so this makes it easier to see the relevant area.
Remove linesprint (st_)
Shatter "The shillelagh engulfs you!"

Don't display engulfs messages for visual beams.
Revert "Remove linesprint (st_)"

This reverts commit ccf31d4db4ab08536c2fa1aaaac39570039dca73.
This reverts commit 9c081e9989210999fec13828c7766572d8f5ccdd.

I have no strong opinion on whether it should be rotatable or not but
hopefully it's possible to come to some agreement on it without removing
the map.
Clarity breathe flame ability description (magicpoints)
Correct a comment.
Don't produce twice as many zombies on D:12-15.

A quirk of dropping the small/large restriction.
Place fallback chance tag vaults when main vault is blocked by [l]uniq tag.

This was occasionally causing hellpanabyss entries to not place.
Revert "Replace `mprf(ch, s)` with `mpr(s, ch)`"

It trades readability and consistency for an utterly negligible bit of
speed.  With the amount of further processing mpr() does, a single sprintf
is nothing.

This reverts commit d9dfa8fc9755fb0a4e8954c7eb94f32fe97b82e0.
Replace `mpr(s, ch)` with `mprf(ch, s)`

Also simplify quite a few cases.

It turns out in >90% cases of non-literals the argument had .c_str(),
which meant it was pointlessly malloc()ed and converted from and to
std::string.  I believe a sprintf is faster, so even the argument of
miniscule speed-up doesn't apply.
Remove the multi-argument version of mpr().
Reverse the order of arguments in mpr_nojoin().

The old one was quite bizarre, inconsistent with mprf().

Only two cases used the default channel (mpr_nojoin() is quite special...),
so I did not add an overload with the default.