C++ client basic performance test

A simple performance test would be very useful to catch design issues as the client evolves. It should take no more than a couple of minutes to run on an "average" developer machine, so that it actually does get run on a regular basis. It should focus on a best guess of what "normal heavy use" of Hot Rod is like. Fancier performance tests that zero in on specific use scenarios can come later.

By default it should run as part of the CTest group of tests against a local Hot Rod server.

Bonus points if (by passing arguments or environment variables) it can also be easily pointed to a remote server, or made to run longer as a primitive soak test.

Additional bonus points if a configurable number of threads can be specified to exercise the client during the test.