Merge pull request #371 from bkng/develop

PLFM-1648: Refactor EntityBundle serialization to SubmissionManager
Change DOI target URL to synapse.org
Merge pull request #372 from eric-wu/release-1.23

Change DOI target URL to synapse.org
Merge pull request #373 from eric-wu/develop

Merge down from release-1.23: Change DOI target URL to synapse.org
Remove the redundant URL encoding
Merge pull request #374 from eric-wu/release-1.23

Remove the redundant URL encoding
Merge pull request #375 from eric-wu/develop

Merge release-1.23 patch to develop -- 	 Remove the redundant URL encoding
WIP: File handles for Submission objects
added DBO test
Added DAO classes. Need to test.
SubmissionFileHandleDAOImplTest