Add X-Socrata-RequestId tracing in query path and row API
Also add 4x4 to headers passed down to QC
Add request ID and 4x4 plumbing to data coordinator update route
Generate request ID if not present, and use header const and method from socrata-http
Plumb requestId through to all DC requests
Use updated socrata-http lib
CR: Change header from 4x4 to Resource
Merge pull request #49 from socrata/velvia/request-id-plumbing

Plumb RequestId and 4x4 down to DC and QC