Add missing hints
According to Aranud on Discord on 07/16/2018:
@IR4 about unused hint images , they didn’t exist in the package. Also, some hints are used and link on images which don’t exists.
for hint images (I already remove the unused hint) these don’t have images under gfx/2d/
there are replaced by the "hand" default images
Attached is a overview of the hints made by Aranud. Crossed ones do not exist, the ones with a tick mark do exist.