Bug 179674 Support time dimension in model
When define time dimension in model, the "itTime" property will be set. However this is not enough. We also need to know to what precision the time value should be evaluated, say, year, month, day, etc. Model needs to be enhanced to support such requirement.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/writer/ModuleWriter.java
* while we first write the ancestor and then the derived ones. The contents
	 * are enclosed in an optional list tag.
	 * 
	 * @param obj
	 *            the container element
	 * @param slot
	 *            the slot to write
	 * @param tag
	 *            the optional list tag that encloses the list of contents
	 */
	protected void writeArrangedContents( DesignElement obj, int slot,
			String tag )
	{
		List list = obj.getSlot( slot ).getContents( );
		if ( list.isEmpty( ) )
			return;
		LinkedList newList = new LinkedList( );
		Iterator iter = list.iterator( );
		while ( iter.hasNext( ) )
		{
			DesignElement element = (DesignElement) iter.next( );
			DesignElement parent = element.getExtendsElement( );
			if ( !newList.contains( element ) )
			{
				newList.add( element );
			}
			if ( parent != null && list.contains( parent ) )
			{
				if ( !newList.contains( parent ) )
				{