Fixes #72 Supports conf-available/conf-enabled on Ubuntu 14

Ok this has been tested on Ubuntu 14.4 and works. I've tried my best for it to keep existing filepaths the same so that people would experience a smooth upgrade, but I'd be happy if someone could give it a try on Ubuntu 12 and/or other OS to confirm.

Is this conf-available/enabled  a Ubuntu thing, or does it come for Debian? It would be trivial to add debian/mint/other support.