Bug 152828 Add the projectFolder property on module
When user doesn't set the resource folder path in designer, there should be a default working path for Birt to manage the report design and find the related resources. A new property should be added on Module: name: projectFolder type:URL This property only can be given from the open design method from session but should not be set after the module initialized. Concern about the backward compatiblity issue, a new method will be added. Open design with a config argument.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/Module.java
* request is silently ignored.
	 * 
	 * @param listener
	 *            the validation listener to remove
	 * @return <code>true</code> if <code>listener</code> is sucessfully
	 *         removed. Otherwise <code>false</code>.
	 * 
	 */
	public boolean removeValidationListener( IValidationListener listener )
	{
		if ( validationListeners == null )
			return false;
		return validationListeners.remove( listener );
	}
	/**
	 * Broadcasts the validation event to validation listeners.
	 * 
	 * @param element
	 *            the validated element
	 * @param event
	 *            the validation event
	 */
	public void broadcastValidationEvent( DesignElement element,
			ValidationEvent event )
	{
		if ( validationListeners != null )
		{
			Iterator iter = validationListeners.iterator( );
			while ( iter.hasNext( ) )
			{