added line to reload the "mean dif file" for each image that needs adjusting. previously this raster was assumed to be held in memory, but if it is large it is written out in the raster temp folder, which is cleared after each image is adjusted, so that the next time it is called it is not available
added line to reload the "mean dif file" for each image that needs adjusting. previously this raster was assumed to be held in memory, but if it is large it is written out in the raster temp folder, which is cleared after each image is adjusted, so that the next time it is called it is not available

jdbcode/LandsatLinkr,DougFirErickson/LandsatLinkr