Commit Briefs
dont "use lib ." in perl; resolve modules normally
fix gotmarc(1) to set PERL5LIB when running in-repo however to load the right GotMArc.pm.
drop unnecessary unveil(".", "r")
These programs don't need to read files in the current directory: GotMArc loads in memory some files at load time, at that point no other accesses to "." are needed.
use $mid.$partno.$ext for attachments rather than random strings
Keeps the attachment file names stable while it also allows to drop the dep on Tempfile, the unveil of /tmp and the fattr pledge promise too.