Return 409 if container with given id in POST exists

Delete unused schema method

closes #269

Remove SCITRAN_RUNTIME_PROTOCOL

This variable was a temporary measure from https://github.com/scitran/core/pull/190 and never fully removed until now.

Ensure timestamps are not blank strings

Move all singletons to new mongo collection

Add /container/id/jobs endpoint

Add some sanity to jobs logic

Only log stacktrace for 500 errors

Fix zipfile bugs, simplify logic

Wrap proj_label in regex escape for query