[sudo-workers] Negation operator in Defaults options

[Todd C. Miller]

The way sudo does matching you need to be explicit if you want
to match everything except certain words.  For example:

Defaults !requiretty
Defaults:ALL,!user requiretty

would do what you want.  I can see how this might be surprising but
I'm afraid it is too late to change this behavior.  Whether requiring
the explicit ALL is bug or a feature is debatable.

I'll add a bit to the sudoers manual explaining this.

 - todd