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
/**
	 * Returns an iterator over the open designs.
	 * 
	 * @return an iterator over the designs
	 */
	public Iterator getDesignIterator( )
	{
		return designs.iterator( );
	}
	/**
	 * Returns an iterator over the open libraries.
	 * 
	 * @return an iterator over the libraries
	 */
	public Iterator getLibraryIterator( )
	{
		return libraries.iterator( );
	}
	/**
	 * Returns an interator over the open libraries and designs.
	 * 
	 * @return an iterator over the open libraries and designs
	 */
	public Iterator getModuleIterator( )
	{
		List roots = new ArrayList( );
		roots.addAll( designs );
		roots.addAll( libraries );
		return roots.iterator( );
	}