Polymophed into a giant and moving onto a boulder's location could
yield "you easily pick it up" (without actually doing so) followed
by "you see a boulder here". It would happen if autopickup was Off,
or if the 'm' move-without-autopickup prefix was used, while either
boulder was included in pickup_types (including when that is set
for 'all') or hero had thrown that particular boulder and
pickup_thrown was On. The check for whether auto-pick should try
on an object relied on its caller verifying that autopickup was On.
pickup() does that for
pickup() -> autopick() -> autopick_testobj()
but moverock() wasn't doing that for
moverock() -> autopick_testobj()
so the logic controlling moverock's message was subverted.
I first thought that logic itself was incorrect and changed the
message. This keeps the new message even though it turned out not
to be cause of the problem.
Fixes#279
07a2c1c813