[Fluxus] colour commits

[Dave Griffiths]

> i committed some colour changes. now all expressions containing colours
>   should expect values in four formats:
>
> (vector .9411 .2352 .145) ; rgb
> (vector .3784 .4411 .9039 .5) ; rgba
> .5 ; greyscale
> (vector 1 .3) ; greyscale + alpha
>
> i also modified the hsv code and made it a bit more logical i hope.
>
> usage of (opacity) is still not perfect. it overwrites colour alpha
> elements of the current state if the opacity value is other than the
> default 1.0. i assumed if the value is not 1.0, the user is using the
> (opacity) function.

To be honest, I'd get rid of Opacity and WireOpacity in the state class
and just get (opacity) and (wire-opacity) to write into the alpha of the
respective colours directly.

I guess in that case (colour (vector r g b)) would just write into the
first 3 elements, leaving the alpha as it was. Does this make any sense? I
haven't been looking into this as much as you have...

It all seems to work well here anyway.

cheers,

dave