Ability to have multiple open ResultSet objects

Adds getMoreResults(int), which takes an argument that specifies whether ResultSet objects returned by a Statement object should be closed before returning any subsequent ResultSet objects.

As a part of the changes, the JDBC 3.0 specification allows the Statement interface to support multiple open ResultSets, which removes the limitation of the JDBC 2 specification that statements returning multiple results must have only one ResultSet open at any given time. To support multiple open results, the Statement interface adds an overloaded version of the method getMoreResults(). The getMoreResults(int) method takes an integer flag that specifies the behavior of previously opened ResultSets when the getResultSet() method is called. The interface defines the flags as follows: