Fixed: CPColor colorWithHue:saturation:brightness: parameters not clamped.

Previously, the parameters to CPColor colorWithHue:saturation:brightness: could be specified below 0 or above 1.0.

Now the values are clamped so that values below 0 are taken as 0 and values above 1.0 and taken as 1.0.
Fixed: CPColor colorWithHue:saturation:brightness: returning undefined.

A hue of 1.0 would cause the CPColor colorWithHue:saturation:brightness: method to return `undefined` instead of a CPColor instance.
Fixed: CPColorPicker not working with fixed CPColor colorWithHue: implementation.