shr.el (shr-insert): Fix the way to fold lines.

shr.el (shr-insert): Fix the way to fold lines.
shr-color.el (shr-color->hexadecimal): Use color-rgb->hex
color.el: Rename from color-lab.el
 (color-rgb->hex): Add.
 (color-complement): Add.
 (color-complement-hex): Add.