Refactor: Load UserConfig as bean

[strehle]

Goal: identityZoneConfigurationBootstrap should not get to many attributes, but load the user config itself and allow there to have extra options

Example: login.checkOriginEnabled is not yet possible to set in CF global because it is / was hidden in the identityZoneConfigurationBootstrap bean. With UserConfig bean allow all options to be configured.

Open: uaa-release should be adopted as well

[cf-gitbot]

We have created an issue in Pivotal Tracker to manage this:

https://www.pivotaltracker.com/story/show/187815406

The labels on this github issue will be updated when the story is started.