pktrace fails on parmesan

[Mats Bengtsson]

I just tried to generate Type1 version of the fonts for
Lilypond 1.5.34 and pktrace stops at parmesanNN. The reason
is that some values fall out of range when calling
mf '\mode:=ljfour; mag:=10.950000; nonstopmode; input parmesan20'
the problem is the same for all the sizes. 

I modified pktrace slightly to keep running even if mf failed, 
but the resulting output is completely wrong for the symbol
noteheads-0solesmes_oriscus and all the custodes-medicaea and
custodes-vaticana symbols. 

  /Mats