[VOLK] Help needed for PR reviews before release

[Johannes Demel]

Hi all,

today I'd like to ask for help to review some PRs before we can do a 
VOLK 2.5.1 release. I'd like to do a release ASAP to still have time to 
get these changes into large distro releases.

I'd like to see better support for automatic publication on Zenodo:
https://github.com/gnuradio/volk/pull/559
you can find prior VOLK releases on Zenodo:
https://zenodo.org/record/4903136
This PR is probably mostly interesting for academia to make it easier to 
cite VOLK if you use it in your work. At least I consider it very 
interesting.
You can add more info about yourself if you like. e.g. ORCID and 
affiliation.

This fix should make it easier for package maintainers to use a system 
cpu_features package:
https://github.com/gnuradio/volk/pull/558

This fix should boost convolutional decoder performance.
https://github.com/gnuradio/volk/pull/475
Since changes to FEC code that affect FER/BER performance are 
notoriously difficult to verify, It'd be great to have more people 
testing this fix. However, this fix is already in use by some users with 
good results.

Some rather obscure kernels are untested for years and probably unused. 
https://github.com/gnuradio/volk/pull/555
I'd like to know if this deprecation approach does not break things for 
anyone.

We need to replace `distutils` in our build system because the functions 
we use are deprecated.
https://github.com/gnuradio/volk/pull/554


These two PRs concern our Boost dependency:
https://github.com/gnuradio/volk/pull/548
https://github.com/gnuradio/volk/pull/557
Either we decide to remove obsolete code in #548 and update our 
requirements, or we finally drop our Boost dependency in #557.
Boost is an optional dependency for old systems that lack 
`std::filesystem` support. The latest CI that required Boost was for 
Ubuntu 14.04. Starting with Ubuntu 16.04, we were able to use 
`std::experimental::filesystem` and drop our Boost dependency. Thus, it 
might be time to finally drop our Boost dependency.

If you have time to look at those PRs and review them, that'd be great.

Cheers
Johannes

--
Johannes Demel M.Sc.
Research Engineer