Enable "wrap" hue detection.

The ignored hue range can now wrap around from a high value (~180)
around to a low value (~0) as if the hue was a color wheel. This allows
more complete segmentation of the red arm, which had hues in both the
low and high ranges.
Change viewer defaults.

The viewer now starts with the minimum area rectangle and region segment
displayed.
Disallow wraparound for saturation, value.

The obj_detect module is not designed to accept wraparound saturation or
value, just hue.
Merge pull request #10 from vancezuo/color-detect

Color detect branch merged.