edge-handling: (1) convert SATUR|BLEED pixels at an image edge into EDGE; (2) drop fully masked rows/columns at the edge of images
edge-handling: (1) convert SATUR|BLEED pixels at an image edge into EDGE; (2) drop fully masked rows/columns at the edge of images

legacysurvey/legacypipe,legacysurvey/legacypipe