Test infrastructure's cleanup methods cause agents process to fail to start

The testing infrastructure attempts to clean up from a previous run of a test. If properties.xml is left around, however, this cleanup will succeed but prevent the agents process from starting in the test. That's because the addShutdownHook() is called, and when resetEnvironment() is called agentStop() is thus invoked, and once agentStop() is invoked agentStart() will just exit next time it is called.

The fix is to make resetEnvironment() reset the agents stop flag so that starting agents will then work.