Proposal: do not show up the dialog(1) by default?

[Vitaly Magerya]

>> I think it is not good idea, because if user don't know regarding
>> options in ports he should do a make config and if it not exist
>> should do a make install in this case we have two action..
>> Maybe other way for fix these frequent "popping" add needed options to make.conf
> 
> I like the suggestion that if the dialog consists only of globally set 
> options (NLS, DOC, etc) then it shouldn't appear by default.

Except the cases when those options pull in additional dependencies.

In those cases either the dialog should be shown, or the options should
be disabled by default.