Patch: Replace use of guile %module-public-interface in Lilypond (Rietveld issue 1160044)
I've incorporated the suggestion from guile
development to replace Lilypond's call to %module-public-interface,
which they are deprecating.
Guile recommend to replace it with module_export_all!, which they will
provide in their code, but provided a recommendation to include in code
for Guile 1.8.7 forward compatibility.