Turtle tasks

[SquidDev]

Certain events in the system, such as item counts falling below a certain level, should trigger a turtle to go and gather that particular resource. Several things to note:

• A further decrement whilst the task is queued/executing in that item's level should not trigger this event again.
• If this resource is not available then there should be a delay before retrying.
• Do we want to go the whole shebang of turtle pathfinding/mapping? Not sure how to implement this whole thing without making it difficult to use: turtle automation is never pretty.

One thing we could do is just define these steps as "crafting steps" and order more items if we drop below a set level.