Image copy finder improvements
- much faster comparison between individual images (up to 4 times faster)
- fixed hue difference - it was not calculated properly if two hues differed by small amount, but one was on the one side of the spectrum, but the other was on the other side. For example 0.002 and 0.998 differ only by 0.004, but in naive approach they differ by 0.996
- probably fixed "time left" for comparison