CheckpointServiceMemory renamed to MemoryCheckpointService
Introduced TimeoutType enumeration
Fixed placement of checkpoints sets/removes in GeneralTaskBackend
Refactoring of Checkpoint service and entities
Refactoring of task start_to_close expiration recovery service
bugfix at checkpoint service
Minor enhancements
Enhancements and bugfixes for Expired task recovery service
Merge branch 'develop' of https://github.com/taskurotta/taskurotta.git
into develop

Conflicts:
	wf-server/src/main/java/ru/taskurotta/server/recovery/TaskExpirationRecovery.java