This is a sub-task of DERBY-210 which covers the following;
1. Eliminates the references to statement classes in the client driver. This allows the statement objects to be garbage-collected once they are not referenced in the application.
2. Clean up the finalizer in the statement classes to avoid synchronized operations.
3. Add the test in the repro derbyStress.java to regression test.
This sub-task solves the memory leak mentioned in the repro "derbyStress.java".