[keycloak-dev] generic model migration

I implemented this as a singleton data item in JPA or Mongo or File. I jsut store the current version. Implementation is in MigrationModelManager and it just checks the currently stored version versus the deployed version. Its all hardcoded at the moment, but does give some abstraction. I think it is good enough going forward. Don't need anything fancy. -- Bill Burke JBoss, a division of Red Hat http://bill.burkecentral.com