Font problems with 2.5.27 on MacOS

[Matthias Neeracher]

It seems the changes in font.scm were harmful to MacOS X. On  
processing, I get:

warning: don't know how to embed "Verdana"="/Library/Fonts/Verdana"

and in the resulting PDF file, the chord names look weird (I believe  
it's Verdana substituted with Courier).

This seems to be related with pango default font lookup, which I  
don't understand very well, and with the fact that native fonts don't  
seem to be handled well by the open source tool chain.

Any suggestions how I could fix this? Should I just add a patch for  
MacOS to revert to Luxi for the sans serif font?

Matthias