oauth2server: authorization flow bug fixes

• Adds redirect URI field to application form.

• Adds validation and setters of redirect uris on model.

• Fixes issue in auth flow when validating scopes.

• Fixes template and context issues in 'Authorize application' view.

• Disables https redirect uri checking when in debug mode.

• Properly handle errors happening during authorize requests.

• Adds test cases for authorization_code, client_crendentials, refresh_token and implicit grant types.

• Adds endpoint documentation in user interface.

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>