Make use of beamer's own frame numbering templates?

[SFr682k]

Version v3.49 of beamer has been uploaded to CTAN recently and is currently spreading around the mirrors. It contains own frame numbering templates (template page number in head/foot).
There is also a template style for page number in head/foot called appendixframenumber being an beamer-internal approach for »replacing« the appendixnumberbeamer package. (see section 8.2.1 of the beamer user guide)

IMO, metropolis should use beamer's templates when they are available. It comes in handy that v3.49 also adds the commands \insertmainframenumber and \insertframenumberinappendix so this version can be detected by:

\ifx\insertmainframenumber\@undefined
    % v3.48 and older: Use metropolis' frame numbering templates
\else
    % v3.49 and later: Use beamer's frame numbering templates
\fi

[matze]

Sounds good but seems a maintenance horror with little gain at the moment. You are welcome to provide a pull request though.