Fixed OauthRepository to accept oauth2_provider engine  parameters
#000 - Gadget index and content should not have any layout.

Tests pass even without these lines. Weird. But, without this change, in
the app, the layout shows, even though it has not been asked for.
#000 - Fix authorization for /admin/oauth/token.

1. It was earlier /oauth/token. Now, it is /admin/oauth/token.

2. Earlier, it was lower in the chain of auth definitions. Now, it has to be
   above, because there is a catch-all /admin/** below it (around line 270)
   which will override this, if it is below.

This change allows the OAuth client to get a token to use for further requests.
#000 - Upgrade joda-time.

jruby-1.7.11 includes joda-time 2.3 (see dependencies section
here: http://maven-repository.com/artifact/org.jruby/jruby-core/1.7.11). Go
was using joda-time 1.6. There is an incompatibility in constructors between
these versions, and some oauth code in token.rb#before_create failed, since
it picked up the older joda-time class.
#000 - Fix another oauth_client_id => client_id issue.

In new engine, it is client_id.
#000 - Add clientId related methods.

getClientId() and setClientId() are called through Rails reflection,
from model_base.rb. Earlier, since the column name was oauth_client_id,
it used to call getOAuthClientId() instead.
#000 - Fix authorization for other oauth routes.

Earlier, /oauth/authorize, /oauth/user_tokens and /oauth/user_tokens/revoke/:token_id
were all authorized by ROLE_USER. As with the earlier commit, now that they are all
prefixed by /admin, the catch-all /admin/**=ROLE_SUPERVISOR rule kicks in for them.

But, they should be ROLE_USER as earlier.
Splitting OauthRepository#saveToken and OauthRepository#saveOauthToken. Adding tests for the newly added methods.
Updating oauth2_provider engine to 1.0.3

Dowloaded release 1.0.3 from https://github.com/sachinsudheendra/gocd_oauth2_provider_engine/releases
Updating Gemfile configuration for oauth2_provider v1.0.3
Merge pull request #493 from sachinsudheendra/gadget-fix

Go gadget for Rails4