[x] Allow skins to specify a button key as the anchor for SetPoint.
Note: This is necessary in 10.0 due to Aura buttons being taller than they are wide to allow other regions to be anchored to the Icon, which is subsequently anchored to the "TOP" of the Button, while the Duration text is anchored to the "BOTTOM" of the Icon.
SetPoint.Note: This is necessary in 10.0 due to Aura buttons being taller than they are wide to allow other regions to be anchored to the
Icon, which is subsequently anchored to the"TOP"of theButton, while theDurationtext is anchored to the"BOTTOM"of theIcon.