This removes libnm-glib, libnm-glib-vpn, and libnm-util for good.
The it has been replaced with libnm since NetworkManager 1.0, disabled
by default since 1.12 and no up-to-date distributions ship it for years
now.
Removing the libraries allows us to:
* Remove the horrible hacks that were in place to deal with accidental use
of both the new and old library in a single process.
* Relief the translators of maintenance burden of similar yet different
strings.
* Get rid of known bad code without chances of ever getting fixed
(libnm-glib/nm-object.c and libnm-glib/nm-object-cache.c)
* Generally lower the footprint of the releases and our workspace
If there are some really really legacy users; they can just build
libnm-glib and friends from the NetworkManager-1.16 distribution. The
D-Bus API is stable and old libnm-glib will keep working forever.
https://github.com/NetworkManager/NetworkManager/pull/308
The strings holding the names used for libraries have also been
moved to different variables. This way they would be less error
as these variables can be reused easily and any typing error
would be quickly detected.