Cleanup README

Some minor re-formatting, updating of copyright, and platform
definitions for now.
Cleanup metadata dependencies

this sorts alphabetically and groups them together for readability
Clarify versions for Ubuntu

Only officially supporting LTS releases for now (gotta pick your
battles!)
Add Ubuntu 14.04 to the platform list
Remove outdated information in CONTRIBUTING
Merge branch 'master' into pdns_0.4.0

Conflicts:
	.kitchen.yml
	metadata.rb