BUKKIT-3357 - Change the inventory of a brewing stand to a BrewerInventory


Leaky ticket: https://bukkit.atlassian.net/browse/BUKKIT-3357
No associated Bukkit PR.

This commit is fairly self explanatory.  All it does is change the inventory in ContainerBrewingStand to CraftInventoryBrewer rather than CraftInventory.  These changes have been tested, and work flawlessly.   Example code can be provided if requested, but this is really a pretty small fix.