Update the test case framework so that it is now possible to suppress anything
written to standard output or standard error while the unit tests are running.
This includes direct references to System.out and System.err as well as
logging performed through the JDK logger.

By default, there will be no change in behavior.  If the
org.opends.test.suppressOutput property is defined and has a value of "true",
then no output will be generated.

OpenDS Issue Number:  903