Check HTTP status before using API responses.
Ask API server for profile information. refs #1815
Provide response[_profile][request_time] if requested by client. refs #1815
Show profile data in log if config.profiling_enabled. refs #1815
Show some params in profiling output. refs #1815
Obey profiling_enabled config. refs #1815
Merge branch '1792-workbench-performance'