Rename Util.deep_dup to avoid confusion

Active Support (and others) use deep_dup for slightly different
behavior.

Fixes #38

Signed-off-by: Stephen Celis <stephen@stephencelis.com>
Document Util methods

We may want to add more later, e.g., "Crepe uses [X] method to do [Y]."

Signed-off-by: Stephen Celis <stephen@stephencelis.com>
Better-document Crepe class methods

Signed-off-by: Stephen Celis <stephen@stephencelis.com>
Document Crepe::Config

Signed-off-by: Stephen Celis <stephen@stephencelis.com>
Remove Endpoint#dup alias

We can (and should) just call clone directly. We're not relying on dup
getting called elsewhere.

Signed-off-by: Stephen Celis <stephen@stephencelis.com>
Improve documentation

Signed-off-by: Stephen Celis <stephen@stephencelis.com>