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/DesignSession.java
* @return the opened library
	 * @throws DesignFileException
	 *             If the file is not found, or the file contains fatal errors.
	 */
	public Library openLibrary( URL systemId, InputStream is,
			ModuleOption options ) throws DesignFileException
	{
		if ( is == null )
			throw new IllegalArgumentException(
					"The input stream must not be null" ); 
		Library library = LibraryReader.getInstance( ).read( this, systemId,
				is, options );
		libraries.add( library );
		return library;
	}
	/**
	 * Creates a new design based on a template. The template name can be null
	 * if no template is desired.
	 * 
	 * @param templateName
	 *            The name of the template for the design, or null if no
	 *            template is needed.
	 * @return A handle to the report design.
	 */
	public ReportDesign createDesign( String templateName )
	{
		ReportDesign design = new ReportDesign( this );
		design.setValid( true );
		designs.add( design );
		return design;