Merge pull request #17 from DavidS/master

Updates for puppet 3.2 compatability && Allow overriding the distro and add dependency repo
Apt-get update before any package installation is back to true by default
Merge branch 'master' of https://github.com/example42/puppet-apt
Keep the apt.conf.d and sources.list.d clean

This allows a more fine-grained approach to cleaning the various .d dirs.