[MIR] resolvconf

As described in https://blueprints.launchpad.net/ubuntu/+spec/foundations-p-dns-resolving we'd like Precise to use a common way of dealing with /etc/resolv.conf

The chosen solution was resolvconf which was heavily improved and cleaned up by Thomas Hood and Steve Langasek so that I've been using it on multiple systems for a few weeks without seeing any issue.

The package itself is basically a bunch of hooks for various piece of software like isc-dhcp-client, ifupdown, ppp, ... to have them all write to /run/resolvconf/interface and then ask resolvconf to generate the updated /etc/resolv.conf
For our desktop installations, Network Manager knows how to deal with resolvconf and properly writes into /run/resolvconf and calls resolvconf without requiring any additional hook.

Once promoted, the package will be added as a dependency to the ubuntu-minimal seed. Users can easily turn it off by making /etc/resolv.conf a file again (the maintainer scripts will turn it into a symlink at install time).

Now as for the usual questions:
Build-Deps: only debhelper
Dependencies: all in main and AFAICS already all installed by default
Security: No issue that I could find, I did a quick check of the file permissions and everything looks good
Ubuntu Bugs: None on Launchpad, all of the previous bugs were either closed by the new version or re-assigned to other packages.
Debian Bugs: Only one bug which is about a lintian override, all other entries are wishlist items.
Maintenance: I'll add this package to my list of packages to monitor/merge/fix for the Ubuntu Foundations team