Updates 2/16/12

- got the MXP OLC into a portable format as an $api object and reduced the need for setup (it automatically presents all props and verbs for a basic setup, with the option for the object's owner to customize the MXP menu string):

- added a central purchaser/seller for each planet and made some changes to selling.  Instead of selling items to the complex terminal players can directly sell items from their inventory.  Stock is tracked by the central purchasers and prices adjusted accordingly (although central ALWAYS makes a profit):