This release improves portability of the code, with a focus on making it work on macOS. In particular, compatibility with MacFUSE was fixed.
Gnulib has been added to the build system, which has allowed most of the
portability code (except for that dealing with hardware flow control for
serial communication) to be removed in favour of using various gnulib
modules (polyfills).
Some minor infelicities that came to light during this process were fixed, including a non-portable printf format that would be wrong on many modern systems.