djcubes J-class upgrade

Scottpkeene\'s J-class model first: http://bridgecommander.filefront.com/file/Scotts_JClass_Cargo_ship;29869
This mod alters the J-class cargo vessel so that it can jettison it\'s cargo with the use of Sneaker\'s MVAM Infinity. An interesting mod, but note: you can only re-intergrate once. You will need