PR: https://github.com/opnsense/core/issues/1077

Content follows, for now just use the sweet template Framework
to get this party started.

We're using "motd.in" so allow replacement during package builds.

Since we have pluggable anchors, this is ready to move to
plugins to shink down the base system a bit.

Te idea is simple, start parsing rules in a uniform way, so we're eventually able to display and alter all auto generated rules.
Because of the large set of legacy code rules, we're going to migrate step by step, leaving the current setup intact.

o Don't look for templates in manufacturer directory
o Allow to use "/" component separator, it's safe
o Hook up the "template list" command

We fall back to the local authentication if not found.

PR: https://github.com/opnsense/plugins/issues/43

* system_console_configure() is really system_login_configure()+
* make a template for sudoers config setting
* move auth template generation to single spot

(pam) switch to pam, with the option to disable our pam helper and switch back to unix mode... for https://github.com/opnsense/core/issues/998

... and it may be that it never will...

(mvc) improve api errors for configuration issues (wrong/missing type) and remove unused return value

We have manifests for packages, no need to duplicate info
about sub-packages that aren't really packages.

Approved by: @adschellevis

PR: https://forum.opnsense.org/index.php?topic=3824