Added in a binary to convert HSV to RGB.

This simplifies things like brightness altering and
displaying a nice, smooth rainbow.

Call as such:
hsv2rgb <Hue> <Hue max> <Sat> <Sat max> <Val> <Val max>
Ex: hsv2rgb 0 1 1 1 1 1 --> 0xff0000 (solid red)

This was written primarily to be used by utils which lack float support

Change-Id: Iaef83033f462b17cc6798af3231c89e36b4d9607