Remove OINFO_FULL from object_info_out()

This removes the flag to ignore player knowledge when getting information about items in favour of setting the knowledge flags on the items to reflect what we want to tell the player about it.  I think it's an improvement conceptually at the cost of a bit of unpleasantness generating spoilers, but the main point is to try and simplify some of the logic in the description functions. 

I have checked spoilers, knowledge screens, stores, etc as best I can to check behaviour is unchanged, but I don't know much about objects to be more certain that there are no knock-ons anywhere.