This provides the following methods:
- dan200.computercraft.turtle.removeUpgrade(id: String)
- dan200.computercraft.turtle.removeUpgrade(stack: IItemStack)
- dan200.computercraft.turtle.addTool(id: String, craftItem: IItemStack[, toolItem: IItemStack][, kind: string])
While it's pretty minimal, it should allow for a reasonable amount of
functionality.
Closes#327 and #97.