Add squeeze support. Fixes camptocamp/puppet-augeas #27

[daks]

This is a quick (and dirty maybe) solution to support Debian squeeze in your Puppet augeas module. This fixes camptocamp/puppet-augeas #27. Tell me if this is good for you.

[raphink]

Hi,

This does not really fix the problem cleanly:

• We do not intend to support Facter < 1.7 in our modules anymore, since not using $::osfamily means we need to match against /Debian|Ubuntu/ and /RedHat|CentOS|ScientificLinux|Whateverelse/. We've been there and we don't want to go back to it.
• If you want to implement that support however (in your branch), I would recommend you drop $::osfamily and replace it with $::operatingsystem instead of adding to the default case which should only fail.