Implement ImageBufAlgo::flip, ImageBufAlgo::flop and ImageBufAlgo::flipflop; remove ImageBufAlgo::transform, use flip, flop and flipflop in oiiotool
LG refactors Robert's flip/flop/flipflop code.
There was nothing wrong with Robert's code, but LG has been totally
overhauling ImageBufAlgo and oiiotool code lately and as a very specific
aesthetic in his head at this point.
Merge pull request #577 from lgritz/flipflop

Flip, flop, flipflop refactor -- combination of Robert's patch and Larry's refactor