CFF font sets

[Werner LEMBERG]

There seems to be a fundamental problem regarding CFF font handling.
Looking into framework-ps.scm I see a function called
`ly:font-sub-fonts'.  If I understand you correctly you want to group
all emmentaler design sizes into a single `FontSet', right?  While
this is possible in PS, it is *not* possible if the CFF is wrapped
into an SFNT data structure: There is no mechanism in SFNT to select a
subfont, and something like `OpenType collections' in analogy to
`TrueType collections (TTC)' doesn't exist.

>From a technical point of view, the emmentaler CFFs used in lilypond
are ordinary PS fonts, similar to the feta or parmesan fonts.  The
current handling of emmentaler fonts causes pstopdf to produce PDF
files which are three or four times as big as files which contain feta
fonts.

Please remove ly:font-sub-fonts and related code and handle emmentaler
equal to feta.


    Werner