keep supporting the DEBUG flag, it is now deprecated, and DPKG_DEBUG is
still supported.

this will be reverted on the 2.x branch, as it is deprecated. this was
mistakenly removed from 1.x so it will be merged there.

This corrects a mistake in the version number introduced in today's
commits.

Conflicts:
	debian/changelog

thanks to Jamie McClelland for spotting the missing unzip dependency

Conflicts:
	aegir.make
	provision.info
	upgrade.sh.txt

we were relying on a function present only in D6 (node_access_needs_rebuild()) - if it is not present, we'll rebuild the node_access tables anyways