Adds a digest method that immediately instantiates providers.

This allows for providers that are needing to not be lazy.
Updated readme for new digest API method.
Improved brevity.
Updated documentation of digest to be service oriented (not provider).
Moved digest documentation to be alphabetic.
Additional documentation cleanup.
Merge pull request #10 from cjsaylor/digest

Add a mechanism for immediately instantiating providers that need not be lazy.