Comment 22 for bug 986534

I have searched the ~widelands/src folder and have found two files that reference checkbox png files:

checkbox.cc - references checkbox.png and checkbox_light_new.png

table.cc - references checkbox_checked.png and checkbox_empty.png

I now plan to delete from the pics folder: checkbox_light.png as it is no longer referenced in the code.
Additionally, I will update the four png files noted above.