Updates prices for alcohol.

As per request of #6482, went through comestibles.json and updated the price of all alcohol items to sensible prices, gathered from extensive googling and looking up online sales.
Some prices (like rum&cola, boozeberry, etc) were calculated from the base cost of the ingredients and a little guessing from the FUN and STIM values.
Compliments (and hopefully doesn't conflict with) #6487.
Also fixes a small error with spiced mead's weight.