HotBars refactor, Equipment add, Crafting start

1) Changed HotBar slot order.
2) Added Crafting HotBar. Once full, it calls "craft" to craft the
items. Crafting system currently does not exist.
3) Default action, /tile/attack, now attacks with equipped weapon. In
other words, it is an alias for the equipped weapon, if it exists.
4) Refactored how HotBars work. Instead of constructing them via
hotbar/setup(), the four kinds of hotbars are now actual types in the
object tree.
5) Equipment HotBar is now structured, with specific places for things
like weapons, and it knows what it's equipped weapon is, etc.