Split metadatahandler into itself and datasethandler. Added some high level dataset cleanup
Workdir creation should not be saved in config since that is shared by datasets
Finalize metadata method
Dataset finalizing method
Only one filehandler instance that can be passed around. Fix later the dependence on different configs
Changed backup metadata method in filehandler
Generalized mongo to json backup method
Fixed the whole filehandler stuff by giving dataset and mdhandler its own filehandler instances