Bug 213126 Add support for DataEngine-leve dataset cache
In many cases the DataEngine-leve dataset cache is useful which ensure that a dataset is executed one time during rendering one report. To support this feature a new dataset property should be added. The Birt customer can choose whether this dataset need to be cached or not by setting the property in deisgn time.
model/org.eclipse.birt.report.model.tests/test/org/eclipse/birt/report/model/parser/JointDataSetParseTest.java
member = (PropertyDefn) columnHint.getDefn( ).getMember(
				ColumnHint.PARENT_LEVEL_MEMBER );
		assertEquals( "4", columnHint.getProperty( design, member ) ); 
		member = (PropertyDefn) columnHint.getDefn( ).getMember(
				ColumnHint.FORMAT_MEMBER );
		assertEquals( "##.###", columnHint.getProperty( design, member ) ); 
		member = (PropertyDefn) columnHint.getDefn( ).getMember(
				ColumnHint.DISPLAY_NAME_ID_MEMBER );
		assertEquals(
				"message.column-hint.username", columnHint.getProperty( design, member ) ); 
		member = (PropertyDefn) columnHint.getDefn( ).getMember(
				ColumnHint.DISPLAY_NAME_MEMBER );
		assertEquals( "User Name", columnHint.getProperty( design, member ) ); 
		member = (PropertyDefn) columnHint.getDefn( ).getMember(
				ColumnHint.HELP_TEXT_ID_MEMBER );
		assertEquals(
				"message.column-hint.help", columnHint.getProperty( design, member ) ); 
		member = (PropertyDefn) columnHint.getDefn( ).getMember(
				ColumnHint.HELP_TEXT_MEMBER );
		assertEquals( "Help me!", columnHint.getProperty( design, member ) ); 
		
		ArrayList filters = (ArrayList) dataSet
				.getProperty( DataSet.FILTER_PROP );
		assertEquals( 1, filters.size( ) );
		assertEquals(
				"lt", ( (FilterCondition) filters.get( 0 ) ).getOperator( ) ); 
		assertEquals(
				"filter expression", ( (FilterCondition) filters.get( 0 ) ).getExpr( ) ); 
		assertEquals(
				"value1 expression", ( (FilterCondition) filters.get( 0 ) ).getValue1( ) );