MFH: Use check-sanity not check-config as its own phase.

Only set DEVELOPER during this phase to trigger warnings. We want to be
able to call stage-qa on our own, so don't set for other phases.
MFH: Disable DEVELOPER waits when running non-interactively
MFH: distclean: Prevent removing all files by accident
MFH: Leftovers: Don't show @dirrm for dirs already in plist
MFH: leftovers: Don't show '@dirrm' for modified dirs
MFH: Fix staging mtree recording message being eaten by pipes
MFH: leftovers: Fix modified dirs/files not showing all mtree output
MFH: testport: Remove PREFIX/package hack for pkg_install, moved to ports r351422.

This was missed in bulk anyhow.