Log Message:
Make the name of nethackdir contain version information (eg. now it's
called nethackdir340). This is to ease the lives of people who wish to
have multiple versions nethack installed at the same time. It is not fully
automated, because doing pkgsrc magic will most likely screw things up
one funny way or another. And we all know that the most important thing
in this world is the nethack scorefile ...

Manually bump version to 3.4.0nb1.