Add Debian support and remove apt cookbook dependency

Add and document support for Debian. Seems to work just fine on Debian squeeze and there shouldn't be any problems on other Debianoids, either.

Also remove the dependency on apt cookbook as this cookbook is not using it for anything. Of course people should have it on the run list to update apt cache, but the less inter cookbook dependencies the better.

Finally add the name attribute to cookbook's metadata to make it possible to use it with [Berkshelf](http://berkshelf.com/). It will probably be a required field in the future.