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/api/ModuleHandle.java
*            the config variable
	 * @throws SemanticException
	 *             if the name is empty or the same name exists.
	 * 
	 */
	public void addConfigVariable( ConfigVariable configVar )
			throws SemanticException
	{
		ElementPropertyDefn propDefn = module
				.getPropertyDefn( CONFIG_VARS_PROP );
		if ( configVar != null && StringUtil.isBlank( configVar.getName( ) ) )
		{
			throw new PropertyValueException( getElement( ), propDefn,
					configVar,
					PropertyValueException.DESIGN_EXCEPTION_INVALID_VALUE );
		}
		if ( configVar != null
				&& findConfigVariable( configVar.getName( ) ) != null )
		{
			throw new PropertyValueException( getElement( ), propDefn,
					configVar.getName( ),
					PropertyValueException.DESIGN_EXCEPTION_VALUE_EXISTS );
		}
		PropertyCommand cmd = new PropertyCommand( getModule( ), getElement( ) );
		cmd.addItem( new CachedMemberRef( propDefn ), configVar );
	}
	/**
	 * Adds a new embedded image.
	 * 
	 * @param image