Eng 2789

This resolves issues that prevented the JDBC driver from working with JMeter.  

The JDBC driver would throw unsupported exceptions when getAutoCommit() and getWarnings() were called, and these aren't expected or handled by Jmeter so it would be fatal.  

getAutoCommit() now returns true, which is accurate for the JDBC interface since we do not support any external transaction control which is the alternative, and there is no third choice, it's true or false.

getWarnings() returns null rather than raising an exception.  This is the valid response when there are no warnings, since there never are any until we implement that feature.  Not all JDBC drivers implement warnings.  It's an alternative to throwing an exception.  It leaves it up to the application to check if there was a warning that perhaps the behavior wasn't exactly as expected, but most JDBC applications are not checking for warnings most of the time.

Finally, I needed to add the zookeeper code to the includes for the client jar file because without them the JDBC driver produces:
Uncaught Exception java.lang.NoClassDefFoundError: org/apache/zookeeper_voltpatches/KeeperException$NodeExistsException.