Bugfix tests

- Fix typo in Overlap Error (Closes JIRA CBDEUCE-211)
- Fix upload block should return X-Block-Reference-Count and X-RefModified (Closes JIRA CBDEUCE-255)
- Fix bug in Block Collection on_post, error message specified PUT instead of POST (Closes JIRA CBDEUCE-263, CBDEUCE-278)
- Adds Falcon 0.2 support since we don't need the falcon.api_helpers any more (never did)