Flipflop -- combination of Robert's patch and Larry's refactor

This subsumes #565 -- LG has refactored it to fully conform to modern IBA aesthetics (the guts are mostly the same, minor changes, lots moved from file to file).

Bottom line is that this gets rid of the awkward IBA::transform in favor of IBA::flip, flop, flipflop, and refactors the corresponding oiiotool commands to use the IBA version.