The previous way was bogus. Use bsd.port.arch.mk to remove
MULTI_PACKAGES instead of having the lack of no_* FLAVOR add them.
Change the no_x11 PSUEDO_FLAVOR to no_tk, since what it does is turn
off the -tk subpackage.
Remove post-install target from Makefile.inc, and use a manually
post-install in every version. This is necessary due to
bsd.port.arch.mk usage.
Noticed by tobiasu@
Guidance from espie@
99dd75e03e