Fix remaining references to DbUserBackend and refresh the documentation.

refs #4786
Provide a cleaner interface for the Authentication Backends

refs #4786
Add controller to handle resource configuration

Add the controller, forms and views to handle the resource configuration.

refs #4786
Add configuration for resources

Add views and controller to handle resource configuration. Add form to edit
several resource types at once.

refs #4786
Fix LdapBackendForm unit test

refs #4786
Merge branch 'feature/resource-config-frontend-4786'