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
/**
	 * Finds a data set by name in this module and the included modules.
	 * 
	 * @param name
	 *            name of the data set
	 * @return a handle to the data set, or <code>null</code> if the data set
	 *         is not found
	 */
	public DataSetHandle findDataSet( String name )
	{
		DesignElement element = module.findDataSet( name );
		if ( !( element instanceof DataSet ) )
			return null;
		return (DataSetHandle) element.getHandle( element.getRoot( ) );
	}
	/**
	 * Finds a joint data set by name in this module and the included modules.
	 * 
	 * @param name
	 *            name of the joint data set
	 * @return a handle to the joint data set, or <code>null</code> if the
	 *         data set is not found
	 */
	public JointDataSetHandle findJointDataSet( String name )
	{
		DesignElement element = module.findDataSet( name );
		if ( !( element instanceof JointDataSet ) )
			return null;
		return (JointDataSetHandle) element.getHandle( element.getRoot( ) );
	}