Missing warning

[Mats Bengtsson]

Could you please add a check somewhere that issues a warning
if Lilypond can't find the feta*.afm files. 

I did a few changes to my login files and to the system
some days ago and then I discovered that Lilypond didn't
print any note heads or other feta font symbols. I got
lots of warning messages about wrong dimensions and 
"nothing to connect ..." and so on, but nothing on missing
AFM files. Since I had been fiddling with the Guile 
installation and some other things, I had to spend some
hours debugging before I found the simple solution.
Of course, this is not a problem for people who use the
official installation procedures, but I prefer to keep
different Lilypond versions in separate directories.

    /Mats