Bug 155509 ModuleHandle findResource method does not support .properties files
There is no fileType for .properties files in IResourceLocator
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/Module.java
public Theme getTheme( Module module )
	{
		if ( theme == null )
			return null;
		if ( theme.isResolved( ) )
			return (Theme) theme.getElement( );
		IModuleNameScope resolver = module
				.getModuleNameSpace( Module.THEME_NAME_SPACE );
		ElementRefValue refValue = resolver.resolve( ReferenceValueUtil
				.needTheNamespacePrefix( theme, this ), null );
		Theme target = null;
		if ( refValue.isResolved( ) )
		{
			target = (Theme) refValue.getElement( );
			theme.resolve( target );
			target.addClient( this, THEME_PROP );
		}
		return target;
	}
	/**
	 * Resets the element Id for the content element and its sub elements.
	 * 
	 * @param element
	 *            the element to add
	 * @param isAdd
	 *            whether to add or remove the element id
	 */
	public void manageId( DesignElement element, boolean isAdd )
	{
		if ( element == null )