Add urls.py for SPA and use namespace
Use existing wait-to-finish url (bug 1036974)
Merge pull request #516 from muffinresearch/1036974

Use existing wait-to-finish url (bug 1036974)
Add MISSING_ERROR_CODE to dev_messages
Merge pull request #517 from muffinresearch/add-missing-error-code

Add MISSING_ERROR_CODE to dev_messages