Tenacity progress and library updates

[Be <be@mixxx.org>]

Hello Debian multimedia packagers,

I have been working hard on Tenacity, the new Audacity fork. In the 
process, I have devendored and updated many of its dependencies, which 
required forking old unmaintained libraries in a few cases. Please *do 
not package Tenacity yet* before we make a release. However, it would be 
great if you could start updating packages which Tenacity depends on. I 
wrote a detailed write up on the library and build system updates on GitHub:

https://github.com/tenacityteam/tenacity/issues/90#issuecomment-901585714