Bug 140542 label can't be displayed without resource file or unmatched key
Steps to reproduce: 1.New a report, add a lable with text "aaa" 2.Add a resource file for the report, set key to "key1", value to "actuate", apply the value to the label 3.Clear the resource file in Property Editor->General->Resource File (or change the key to "abc") 4.Preview the report Expected result: 1.Display label text "aaa" on preview or 2.Give a warning message to say resource file is not found or unmatched key Actual result: Nothing displays on preview
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/Module.java
* Sets the system id of the module. It is the relative URI path of the
	 * module.
	 * 
	 * @param systemId
	 *            the system id of the module
	 * 
	 */
	public void setSystemId( URL systemId )
	{
		this.systemId = systemId;
	}
	/**
	 * Finds a theme in this module and its included modules.
	 * 
	 * @param name
	 *            Name of the style to find.
	 * @return The style, or null if the style is not found.
	 */
	public Theme findTheme( String name )
	{
		ElementRefValue refValue = moduleNameSpaces[THEME_NAME_SPACE].resolve(
				name, null );
		return (Theme) refValue.getElement( );
	}
	/**
	 * Returns the theme of the report design/library.
	 * 
	 * @return the theme of the report design/library
	 */
	public Theme getTheme( )