DDF-669 DDF-670 DDF-682

DDF-670 - Restyles the admin application modules.  Setup initial application selection page for Jeren and Sam's work.

DDF-669 - Created Feature management backend API and Feature UI via
config plugin.

DDF-682 Created configuration plugin API framework.  Adjusted
configuration UI to work within a Configuration Plugin.
This will log duplicate exception message information in the log.  I would suggest not including the getMessage or the name of the method but instead include a more admin friendly explanation like "Unable to map features to repositories" for example.