Resolve issue #100 re: programmer error -- provide a useful diagnostic message if a type in the app's lib/types.js is misconfigured (i.e. is not an instance of `Type`).
Resolve issue #100 re: programmer error -- provide a useful diagnostic message if a type in the app's lib/types.js is misconfigured (i.e. is not an instance of `Type`).

kanso/underscore,kanso/underscore