Cleanup the README links and language
Merge pull request #65 from opscode/sethvargo/fix_readme

Cleanup the README links and language
Pin chef to a version that supports Windows with Ruby 2.0.
Merge pull request #66 from opscode/sersut/chef-pin

Pin chef to a version that supports Windows with Ruby 2.0.
Update CONTRIBUTING.md document.
Collect graph modifications and solution constraints from policyfile
Extract policyfile DSL to its own class
Implement graph solution in policyfile compiler