Fix test for ignore-ownership flag on %p volume

`diskutil` takes a volume (mountpoint) only, not a directory or
location on the volume. Parse `df` to find mountpoint of %p. Maybe
this test has never worked? Our test-harness is not verbose enough to
report the skip.
Check that target volume has permissions enabled early in bootstrap

Bootstrapping fails (weird errors when dpkg calling tar to unpack
.deb) in bootstrap phase 3, which is before fink itself runs its
test-suite. Clone t/10features/volume.t permissions-enabled test into
bootstrap shortly after user chooses %p (before any other actual
building begins).
Fix weird grammar in error message

"Nothing ${cmd}d" tries to conjudate $cmd, but that variable may
contain flags as well as a simple verb (Nothing remove --recursived).
Clean up some variable-scoping, document possibly-unreachable cmd option
Fix for bindist to work with darwin-x86_64 since apt converts _ into %5f
Manpage fixes.
This is just a note of somethign that needs to be added for newer apt.  We will likely need an pat version function to enable this, or start signing our bindist before it's released
Merge branch 'master' of git://github.com/fink/fink