IdStory Identity Manager

New identity attribute 'state' will be added:
- represent current identity state, respectively state of identity contracts
- will be used for long running task, which needs react to it - e.g. when identity starts to be valid, then new password for their account should be generated and send in notification (#666)
- state will be synchronized automatically by contract's state and validity (by event processors or LRT)
- can be used for reports
- attribute 'disabled' will be controlled by this state automaticaly - the same behavior as contract's state.
- identity can be disabled manually - will be state value, but will be controlled by standalone button. When identity will be enabled again, then state will be evaluated again.

Implementation notes:
- enumeration IdentityState