Add a "roll-over foreColor" option to relevant skin elements
A number of recent skin designs I've seen, or worked on, have wanted to have a colour scheme for buttons whereby a dark foreColor is used in the non-rolled over state, but when rolled-over they want the text changed to a light foreColor to better suit the roll-over graphic elements for those buttons. It would be good if we could have the skins extended to allow an alternate foreColor to be defined for rollOver foreColor, as can currently be defined for disabled foreColor.