Ubuntu shouldn't be using debian backports by default.
This was written by Anoine Beaupré, but split from the commit "move
backports to snippets" since the change is unrelated and needs to be
more visible in the commit history.
* Removes dependency on lsb-release and/or Facter >1.7
(values are based on $::lsbdistcodename, when available)
* Simplifies maintenance: only lib/facter/util/* require updates as new
releases are made
Caveats:
* apt::codename is removed; to override debian_* facts, set the
FACTER_debian_codename environment variable for puppet
* If tracking unstable, make sure lsb-release is installed, as other
methods can't tell between testing and unstable
