There's no reason to roll-your-own extraction target, the stock target
works fine. Remove and and adjust do-install accordingly; there's not
change the pkg-plist.
While here, remove RVER derivative of PORTVERSION. This looked wrong to
me -- I doubt the RVER will end in ".164" after the PORTVERSION is
incremented. If anything, the PORTVERSION would be derivative of RVER,
but for now I just have two seprately defined variables. Also, unmask
installation commands.