fail if junitclass list of tests is empty (#1015)
fail if junitclass list of tests is empty (#1015)

When running ant junitclass -Djunitclass=TestFoo
don't say "all tests passed" if the set of tests represented by ${junitclass} is empty.

This may be mathematically correct but it covers up typing errors.
VoltDB/voltdb,VoltDB/voltdb,VoltDB/voltdb,VoltDB/voltdb,VoltDB/voltdb,VoltDB/voltdb,VoltDB/voltdb