Bug 179737 The MeasureHandle should be able to provide data type info
We are now allow user input expression as measure expression. However this brings difficulties in determine the data type of a measure expression evaluation result. We need MeasureHandle to be enhanced to include the data type info. Please note that data type "any" is not accepted.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/writer/ModuleWriter.java
.getVersionManager( ).getVersion( ) );
		getModule( ).apply( this );
		getModule( ).getVersionManager( ).setVersion(
				DesignSchemaConstants.REPORT_VERSION );
	}
	/**
	 * Write an XML attribute from an element property.
	 * 
	 * @param obj
	 *            the element that has the property
	 * @param attr
	 *            the XML attribute name
	 * @param propName
	 *            the name of the property to write
	 */
	protected void attribute( DesignElement obj, String attr, String propName )
	{
		ElementPropertyDefn prop = obj.getPropertyDefn( propName );
		assert prop != null;
		Object value = obj.getLocalProperty( getModule( ), prop );
		if ( value == null )
			return;
		String xml = prop.getXmlValue( getModule( ), value );
		if ( xml == null )
			return;
		writer.attribute( attr, xml );
	}
	/**
	 * Writes one property entry of an element.
	 *