*8262* add galley type to article galley
*8262* introduce articleGalleys plugin category
*8262* genre registry additions for style sheets, images category tweak
*8262* article file manager tweaks
*8262* include galley type on article galley form
*8262* add link action for managing dep files to galley grid, other changes
*8262* introduce artwork delegates
*8262* modify handler & templates, remove code moved to articleGalley plugins