GSoC 2020: backwards compatibility

[Owen Lamb]

Hi all!

Daniel drew my attention to the fact that my work doesn't keep backwards
compatibility with other fonts encoded in the LilyPond manner, such as
Gonville. He made a good point--it's definitely worth it to continue
supporting the old format until Emmentaler reaches a reasonable SMuFL or
"extended SMuFL" state that we can officially recommend be used by other
fonts.

That said, it would be difficult for me to bring backwards compatibility
back before Friday (or Monday, if it comes to that).

Werner (and the community in general), is backwards compatibility important
enough that I should try to take care of it before the deadline?

Thanks,
--Owen