modifies storage vars again

Created by: Intigracy

changes #9354's modifications to it due to an issue brought up in #11721 (closed) by kurfurst

can_only_hold no longer ignores fits_max_w_class, meaning you need to put the item you want to fit in there into fits_ignoring_w_class if you want it to fit.

This will affect, to my present knowledge, just the following:

Fire extinguishers Socket wrenches

They'll no longer fit in regular toolbelts.

fixes #11721 (closed) obviously