Extract without output dir puts .nar in cwd

[SimenB]

If I do nar create --executable --os linux --arch x64 --node 6.9.2, then do mkdir -p new-dir/out && mv archive.nar new-dir && cd new-dir, and run ./archive.nar extract -o out I get

$ ls -la
drwxr-xr-x  4 root root     4096 Dec  8 20:57 .nar
-rwxr-xr-x  1 root root 22701019 Dec  8 20:40 archive.nar
drwxr-xr-x  4 root root     4096 Dec  8 20:58 out

.nar is not included into the output directory.

[h2non]

I've decided that I don't want to change this behavior due to backward compatibility side-effects.

.nar folder is part of the executable execution routine. I can consider changing this in v0.4.0, but not in this minor version.