Partial Brewing Implementation

-Progress arrow now correctly updates
-Proper inventory logic (shift clicking, slot-setting, etc.) implemented for BrewingStandInventory
-Some items can be brewed (Nether Wart+Water Bottle --> Awkward Potion; Awkward Potion + Ghast Tear --> Regen Potion; etc.), many potion recipes still need to be implemented - look at GhastTear to see how it is done