Don't automatically recalculate crafting plans

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update the visual display to show that the plan is out of date, and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.

src/client/models/crafting/crafting_step.coffee

@@ -27,7 +27,7 @@ module.exports = class CraftingStep
 
     addToolsTo: (targetInventory)->
         for stack in @_recipe.tools
-            targetInventory.add stack.itemSlug, stack.quantity
+            targetInventory.add stack.itemSlug, stack.quantity, insert:true
 
     completeInto: (targetInventory)->
         for stack in @_recipe.output