Add a small harness for Benchmarking code

Approver's checklist:

• The author has submitted the FSF Copyright Assignment and is listed in AUTHORS
• There is a test suite reasonably covering new functionality or modifications
• Function naming, parameters, return values, types, etc., are consistent with existing code
• This feature/change has adequate documentation added (if appropriate)
• No obvious mistakes / misspelling in the code
• Add the copyright notices to all the files

The new benchmarking code is here.

This time around, all you need to do is, $ bash ./new_benchmark <benchmark-name> (Currently, http1 or http2). Everything else is automatic :)

Once we agree on this, I'll remove the old scripts, and rename this to just benchmark