RGB2HSL
RGB2HSL Convert an RGB color record to its HSL equivalent
#include <Picker.h> Color Picker Package
void RGB2HSL(rColor,hColor);
RGBColor *rColor; is the starting color record
HSLColor *hColor; is the resulting color record
The RGB2HSL procedure converts an RGBColor record to its equivalent
HSLColor record.
rColor is the RGBColor record to be converted
hColor is the resulting, equivalent, HSLColor record
Returns: none

Notes: A SmallFract is the fractional part of a Fixed number, can be assigned
directly to and from a short , and represents values between 0 and 65,535.
By using a SmallFract while short is used as an unsigned integer-sized
value (as is the case with RGBColor), the Color Picker sidesteps
problems with sign extensions in the conversion math.