Add autocrafting

[fechan]

The best way I can think of adding this is:

1. User connects crafty turtle to wired network
2. User runs a turtle-side script that advertises it as a SIGILS autocrafter via rednet to the main SIGILS computer
3. SIGILS editor shows autocrafter as a special Autocrafting node where the user can select which items go in which crafting slots
4. User can drag a pipe from a slot group to the autocrafter node to use as an input inventory
5. User can drag a pipe the autocrafter to a slot group to use as an output inventory

It might be a good idea for the turtle to empty itself via the output pipe before trying to craft stuff, to avoid bugs? For instance, recipes involving water buckets might cause the bucket to remain the crafting grid which would screw things up if it wasn't emptied.

The input pipes would need a special pipe mode that move items directly to the correct slots, but this should be pretty easy since the destination slots are determined ahead of time.

There is a hitch where autocrafters cannot feed into each other, since you can't transfer items from a turtle directly to another turtle with the generic inventory API, only between a turtle and a generic inventory.