[boost] [gil] added hsl color space to gil

From: Tom Brinkman (reportbase_at_[hidden])
Date: 2007-04-30 22:16:53

The HSL color space is a needed addition.  I took a quick look and I'll try
it out soon, but it looks good.  It follows the lead of the adobe gil
developers and uses mpl::vector3, which I think is a pretty clever use of
mpl.  I'll give some more feedback within a week or so.