Real Time Data

Added support to get real time and historical data for products.

added delete_order, modified getdata for portfolio, modified orders

Added the methode delete_order to delete open orders with an orderId.
Added a parameter to the orders methode to filter only open orders.
Added a parameter to the getdata methode using the portfolio parameter to filter products with a size greater than zero.

added product_info function

The product_info function returns information concerning a specified product ID