default OPTIONS aren't the default when BATCH is set

[Thomas-Martin Seck]

* Sergey Matveychuk <sem at ciam.ru> [gmane.os.freebsd.devel.ports]:

> There is a workaround while it's not fixed:
> OPTIONS=        SOME_DEFAULT "..." on
> WITH_SOME_DEFAULT?=     yes

That looks bogus to me. The ?= does not make sense for variables
which are checked for definedness only (?= is the same as = since you
cannot 'unset' the variable on the commandline) and IMO it is sufficient
to fix the port's options parser to check for WITHOUT_OPTION_FOO when
'foo' defaults to 'on'. At least this is how I do it in my ports.