Fix to make preload for external dataset agent idempotent
Bumped ion-definitions
DAMS extensions to edit external dataset agents and instances
Bumped ion-definitions
Bumped ion-definitions
Updated TESTED_DOC
Bumped ion-definitions to REL2.0
Merge pull request #1457 from mmeisinger/fix_glpre_r2

Fix to make preload for external dataset agent idempotent /REL2.0
Bumped ion-definitions to REL2.0
Merge pull request #1459 from mmeisinger/fix1262_daedit_r2

OOIION-1262: DAMS extensions to edit external dataset agents and instances /REL2.0
Moves the metadata about coverages into the object store

- Adds new method to dataset management to deal with latest data (and
  changes).
- Updates ingestion and dataset management to use the object store for
  metedata, avoids loading a coverage at all cost for metadata.
- Updates visualization and data product mgmt to use new format.
- Test(s)
Removes get_last_update
Fixes dmend2end tests