Started work on Weapon Guis

Weapon Slots:

-Work on Weapon Slots, way more efficient
-Use addSlot(x, y) in Craft's constructor
TODO
-Change the addSlot(x, y)s to the correct coordinates

Hotbar:

-Added Hotbar.java for using the Hotbar gui
-Hotbar now renders the craft's weapons
BUGS
Previous commit did not push :(

Did weapon gui slots (on craft) and hotbar stuff
Hotbar needs anti aliasing and causes a lot of lag for some reason