* The "Show Plan for Tools" link should open a new window each time
it is clicked (i.e., don't re-use the same window)
* Further customize the title of the crafting page to give some
indication of what is being crafted
Instead, any time a change is made which invalidates a crafting plan,
update the visual display to show that the plan is out of date, and
add some extra affordances to recalculate.
* When evaluating a plan, only give the pass-through treatment to
items if the step they're part of was actually executed
* When marking a step "complete", ignore passthrough items