This should have been done in
221d3a97 "; Revert "Recognize
graphicsmagick in image-dired"
'image-dired-cmd-pngnq-options', 'image-dired-cmd-pngcrush-options',
'image-dired-cmd-create-standard-thumbnail-options'
-*** Recognizes more tools by default, including pngnq-s9, OptiPNG, and gm
+*** Recognizes more tools by default, including pngnq-s9 and OptiPNG
*** 'find-file' and related commands now work on thumbnails and
displayed images, providing a default argument of the original file name