Error: Illegal entry in bfrange block in ToUnicode CMap

[Phil Holmes]

More looking at make doc output.  This set of error messages ("Error: 
Illegal entry in bfrange block in ToUnicode CMap") has been discussed 
before, and it's not a Lilypond issue, it's to do with texi2pdf on Ubuntu. 
Nevertheless, it does litter the output of make doc with hundreds of error 
lines, which isn't good.  A prime culprit is notation, and the errors come 
from 2 parts of the documentation: 3.3.3, where we're supposed to be showing 
Cyrillic, and the list of special characters in Appendix A11.

If you check a PDF for 3.3.3 you'll see that the Cyrillic isn't even there, 
and ditto the special characters: № is missing (twice) as well as 
&ng; and &NG;.  It looks like they not only cause an error, they don't get 
generated at all, which makes the PDF docs look odd.

I'd personally like to get rid of the errors, but don't know how to fix the 
problem.  It's almost certainly an upgrade to something like poppler.  I 
don't think we should have docs purporting to show Cyrillic but not actually 
doing so.

--
Phil Holmes