The Browncoat Update - Give BuyMenu more scriptability and customizability

[pawnishoovy]

Let scripts open the BuyMenu for a specific player with a bunch of options.

Some ideas:

Disable X object tab
Enforce player team tech only
Price multiplier
Disable/enable sending delivery craft like normal

Clicking "buy" would trigger a callback function on the object that originally called that buy menu. Something like:
OnBuyMenuPurchase(itemList, collapsedItemList, totalPrice) etc etc

Other actions might have callbacks too but I don't have any ideas.

The specifics will need to be figured out so we don't have buy menus opened by different scripts triggering functions on things that don't want functions triggered.