DAS & 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 stage default data
  - schedule cronjobs:
      * das/manage updatedata - to periodically load stagedir, similarly as it has been up to now
      * ~~das/manage fetchdata (and there should be a switch whether this automatic updating is enabled)~~
         - the dasmap & keylearning updates must be initiated semi-manually, to have some supervision.
* **das/manage new commands**:
  - fetchdata: download data from repo and stage it for updating - to be run manually
  - 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 and mongodb/manage - does 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.