PDF order & packing-slip

This is an update for LiteCart versions 2.6.0 and newer.

Create a PDF for your order & packing-slip

Note: in order to create a neaty pdf, when an order has more then 13 products, i virtual modified file "printable_order_copy" and "printable_packing_slip" to create multiple pages, in which every page has it's own header & footer. This has some influence on the original printable_order_copy file, printable_packing_slip file and print job