initial changes to support mongodb separation and downloading metadata (DO NOT MERGE YET)

DO NOT MERGE YET: FOR DISCUSSION

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I propose to proceed something like this:
* das/deploy:
  - on deploy call manage/resetdata to load defaults
  - schedule cronjobs: 
      * das/manage updatedata
      * das/manage fetchdata (and there should be a switch whether this automatic updating is enabled)
* das/manage new commands:
  - fetchdata: download data from repo and stage it for updating
  - updatedata: check staging area for updates, is run periodically via cron (call existing das_db_import)
  - resetdata: load the default data contained in DAS's RPM  (call existing das_db_import) 
* mongo/deploy - does nothing specific for DAS
* mongodb/manage - nothing specific for DAS
  - optionally, on reboot possible power failure, could consider resetting dasdb to the default state which either was included in DAS rpms, or in the last successful update (not implemented), but if we had real separation this would be harder to signal / identify. now DB is updated from DAS side (server containing DAS), not from mongodb.