Added Verb support and reorganized imports.
Verbs allow Options classes to be nested inside other Options
classes and referenced as a verb referring to what would
otherwise be the first positional parameter. All subsequent
parameters (named or positional) belong to the Options class
specified by the verb's type.

Imports were reorganized to put all classes a user would need
for configuration into the 'clipr' namespace (instead of
nested clipr.* namespaces).