UID and Label based uploads

Restrict length of subject fields

Remove testing change unintended for commit

rename schemas
refactor and eliminate some duplicate code in placer.py

Create or recreate ttl index on db intialization

Expire cached token after 7 days

Consistency checker

Relates to #220

Update to latest testdata commit, containing more realistic session labels

Explicit schema versioning and upgrades

Adding versioning to db schema. For any future changes
in the schema, bump CURRENT_DATABASE_VERSION and add
another condition block containing the relevant mongo
calls for that incremental schema upgrade.

Add travis-based integration tests

allow access to containers for all users

Add 'public' as a propagated property for projects

Sensitive data like subject firstname and lastname will be left off.
Also file contents won't be available.