New sensor: inventory tracker

[narc0tiq]

Via http://www.factorioforums.com/forum/viewtopic.php?p=107797#p107797, a sensor to track how much of the "basic" crafting materials one has in one's inventory.

Relatedly, a sensor could sum up all the stacks of something you have in your hand to tell you how many remain in total (for things like conveyor belts, of which it is not uncommon to have multiple stacks).

[narc0tiq]

Explanation: 'help-wanted' is redundant; pull requests are accepted for any of the issues.

[jocker-il]

I have an enhancement for this - one box showing small white boxes with ability to choose the five/six items you want most to craft and the amount you can make with the content of your inventory

something like this (from AutoTrash mod):

or this (from the vanilla inventory/crafting screen):

I prefer the later, but will do with the former :)