MODE-2277 Added the ability to avoid performing versioning and locking validations if these are not used in a repository.
MODE-2277 Changed & simplified the thread-safe approach for RepositoryChangeBus, to avoid deadlocking when a listener attempts to un-register itself.
Merge pull request #1204 from hchiorean/MODE-2277-3.x

MODE-2277-3.x Ported MODE-2277 from master