Relicensing test_set_editor

Hi Bryan,

I was wondering: would you be okay with relicensing your test_set_editor()
function from git’s test harness as GPL-2+?

The functionality is useful, so if that is not okay, I guess someone
who hasn’t read the code would have to reimplement it[1].  I thought I
should ask because clearly you have not disappeared from the face of
the planet. :)

Thanks for your work, and sorry for the bother,
Jonathan

[1] Context: the Notmuch mail project would like to use git’s test
harness.  The ack-collection for a patch to change the license to
help with uses like this is being tracked here:

https://git.wiki.kernel.org/index.php/Test-lib_reclicensing