An alternate solution for missing stencil routines

[Patrick McCarty]

Hello,

This is a followup to the patch I posted:
http://lists.gnu.org/archive/html/lilypond-devel/2009-06/msg00453.html

Perhaps it would be better to define "empty" stencil routines instead
for every one that's missing; this technique is already used, for
example, in output-svg.scm:

  (define (grob-cause offset grob)
    "")

Maintenance would be higher, but since there are only 3 output
backends, the amount of work required is pretty low anyway.  Then,
removing the obsolete code could be a separate patch.

Thoughts?

Thanks,
Patrick