This improves the HTML rendering.
But it also causes a lot of non-resolvable linkends warning when rendering a
separate manual pages into roff/mman. The messages are harmless, but still
a bit ugly.
When performing NM package upgrade the new version of nmcli will be immediately
available while NM daemon will not, as it would not restart in order to avoid
to disrupt connectivity. This could create issues with tools leveraging
on nmcli output (till reboot). As apart from this case it is very unlikely
that a user can have this nmcli / NM daemon version mismatch situation,
the check could cause more harm than benefit in real user case
scenarios.
https://bugzilla.redhat.com/show_bug.cgi?id=1291785
This way it's consistently used across all manual page without a need
for XSL templating.
Also, the entities file could in future possibly be used to template the
build-time configurables such as filesystem paths or bug tracker URL.
