WIP add-date-created script.
Various fixes
Add upgrade step for document references.
Add document to upgrade command; make item type an argument.
Bump document version to 2 as reference regex has changed.
Set permissions for all characterization states.
Don't make IN PROGRESS / PENDING DCC REVIEW characterizations public.
Merge pull request #173 from ENCODE-DCC/hotfix-date-created

Hotfix date created