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
* @param obj
	 *            the design element
	 * @param resourceKey
	 *            the resource key value
	 * @param resourceValue
	 *            the user-visible resource value
	 */
	protected void resourceKey( DesignElement obj, String resourceKey,
			String resourceValue )
	{
		resourceKey( obj, resourceKey, resourceValue, false );
	}
	/**
	 * Writes the resource key.
	 * 
	 * @param obj
	 *            the design element
	 * @param resourceKey
	 *            the property name of resource key
	 * @param resourceName
	 *            the property name of user-visible resource
	 * @param cdata
	 *            whether the values is written as CDATA
	 */
	protected void resourceKey( DesignElement obj, String resourceKey,
			String resourceName, boolean cdata )
	{
		PropertyDefn nameProp = (ElementPropertyDefn) obj.getDefn( )
				.getProperty( resourceName );
		assert nameProp != null;