Bug 950467, part 1 - Iterate continuations only at the outermost level, recursing into each.  r=roc
Bug 950467, part 2 - Only call GetFontFacesForText for the first text continuation, but with aFollowContinuations=true, and optimize GetFontFacesForText for that case.  r=roc
Bug 950467, part 3 - Remove the unused aFrame param from nsFontFaceList::AddFontsFromTextRun.  r=roc