Merge branch 'ijg' into dev - Restore GIF read/compressed GIF write support from jpeg-6a and jpeg-9d. - Integrate jpegtran -wipe and -drop options from jpeg-9a and jpeg-9d. - Integrate jpegtran -crop extension (for expanding the image size) from jpeg-9a and jpeg-9d. - Integrate other minor code tweaks from jpeg-9*