Denemo and FreeBSD

[Luis Falcon]

Dear denemo team

Congratulations for the package! I have installed the package (2.0.6) on
FreeBSD 13.1 and it works quite well. I tested MIDI, musicXML import,
PDF ouput... everything runs smoothly :)

There are some minor portability issues that I've run into and that can
be tackled. For instance, when starting up denemo, the following: 

"/proc/self/exe: No such file or directory" flood the terminal.

The /proc/self/exe could be mapped to the FreeBSD equivalent
(/proc/curproc), or use a OS independent function.

I am curious who is also using Denemo in FreeBSD. The current
port (2.0.6) is quite dated (2016), and it would be great to push it to
the latest version.

All the best,
Luis