split all classes/defines out into their own .pp files

Per section 11.1 of the puppet style guide:

All classes and resource type definitions must be in separate files in the
manifests directory of their module.

http://docs.puppetlabs.com/guides/style_guide.html#separate-files
Merge pull request #8 from jhoblitt/one_class_per_file

split all classes/defines out into their own .pp files