Add "RESULT SETS 1" in the stored procedure create statement

Add "RESULT SETS 1" in create statements for stored procedures in src/org/hibernate/test/sql/hand/custom/db2/Mapping.hbm.xml

Before:
CREATE PROCEDURE HIBDB2TST.selectAllEmployments ()
CREATE PROCEDURE HIBDB2TST.paramHandling (IN j SMALLINT, IN i SMALLINT)
CREATE PROCEDURE HIBDB2TST.simpleScalar (IN j SMALLINT)

After:
CREATE PROCEDURE HIBDB2TST.selectAllEmployments () RESULT SETS 1
CREATE PROCEDURE HIBDB2TST.paramHandling (IN j SMALLINT, IN i SMALLINT) RESULT SETS 1
CREATE PROCEDURE HIBDB2TST.simpleScalar (IN j SMALLINT) RESULT SETS 1

Without that, DB2 returns a SQL Warning code 464 and no result sets.

See: http://publib.boulder.ibm.com/infocenter/db2luw/v8/index.jsp?topic=/com.ibm.db2.udb.doc/ad/c0009166.htm

This causes the tests testScalarStoredProcedure, testParameterHandling and testEntityStoredProcedure under org.hibernate.test.sql.hand.custom.db2.DB2CustomSQLTest to fail.