Implement partial brewing. Most of the brewing reagents still need to be implemented, but you can now successfully brew Awkward Potions using Nether Wart and Water Bottles.

Signed-off-by: aPunch <theapunch@yahoo.com>
Merge pull request #536 from aPunch/master

Partial Brewing Implementation
Stopped resetting of gamemode during login.
The way it was prior to this was basically always take the World's
gamemode specified in worlds.yml and apply it to the player when they log
in. This change makes it so if its null, apply the world's default
gamemode but if they have one specified VanillaData.GAMEMODE (Creative, Survival, Adventure) then to use that instead.
Signed-off-by: Steven Downer <grinch@outlook.com>