Implement get() and update()
Move configuration to StackConfiguration
Add an important comment
Move more configuration from code to EzidConstants
Allow retrying on DOI errors
Replace null with NotFoundException
try-catch NotFoundException
Merge pull request #370 from eric-wu/develop

Implement get() and update() and config change
PLFM-1648: save entity + file handle + annotations with Submission
Removed File Handle ID from Submission
Add serialized EntityBundle to Submission
Require eTag for Submissions. Need to add integration test.
WIP: need to fetch Bundle at service level
etag verification on Submission
Require ownership or admin rights to get Submissions
public-access getAllSubmissionStatuses() methods