This brings down the test run from 108 sec to 15 sec.
There is an occasional port conflict because of the nature
the next port is chosen. So far it seems rare enough to live
with it.
TestAgent will replace the following mechanisms to
start test agents in subsequent requests:
* makeAgentXXX
* makeDNSServerXXX
* makeHTTPServerXXX
* testServer
* httpTest