Add logging of query IDs via QueryLogIterator class

[SethSmucker]

Create QueryLogIterator class that logs a query's ID to the TServer logs

• Add QueryLogIterator to DefaultQueryPlanner
• Add tserver.logging.active to QueryParameters, used to turn logging on and off
• Add tests for QueryLogIterator and TServerLogging

Resolves #2305

Updated the PR to merge code from NSA/log-iterator to NSA/origin instead of from SethSmucker/log-iterator.

[billoley]

How to update thread name and restore old name
Also how to add and remove a value to the MapedDiagnosticContext (MDC)

String oldName = Thread.currentThread().getName();
Thread.currentThread().setName(oldName + " -> " + queryId);
MDC.put("queryId", queryId);
try {
    // call corresponding method of the source
} finally {
    Thread.currentThread().setName(oldName);
    MDC.remove("queryId");
}

Keep the start/stop logging in seek and next, but it's overkill in the others
Add the code to change/restore thread name and add/remove MDC in all methods that are overridden from the base class and which call that method on source