browser: add colors for WebKit browsers
browser: add colors for WebKit browsers

Based off of the implemention from #67, except this one
matches the Node.js colored output exactly, including the
trailing `diff` value.

zacronos/debug,visionmedia/debug,jabaz/debug,elliottsj/debug,CantemoInternal/debug,elliottsj/debug,zacronos/debug,CantemoInternal/debug,jabaz/debug