Added OAuth2 features to AuthenticationEntity

- Added tests to indicate expected state
- Updated entity to allow OAuth2 values
Added OAuth2 awareness to the AuthenticationModel

- Assumes that configuration is in zf-mvc-auth.authentication.oauth2
- Writes route configuration to global file
- Writes all other information to local file
- Ensues that routing information is removed when authentication is
  removed
Added information on OAuth2 resources

- as part of `authentication` resource
CS fixes (trailing whitespace)
Merge branch 'feature/oauth2-api' into feature/oauth2-ui

Implements admin API for zf-oauth2
Added OAuth2 config UI

- as part of Authentication UI
Return a 204 from the authentication resource

- when no configuration is present. Adjusted the client code to handle this as
  well.
Merge pull request #20 from zfcampus/feature/oauth2-ui

Merging addition of oauth2 UI