unnecessary /space glyph in ps output

[Werner LEMBERG]

Consider this input:

  \header {
    footer = ""
    tagline = ""
    copyright = ""
  }

  { c' }

If you convert this with

  lilypond --ps

you can see the following in the created PostScript code:

  5.6906 -2.8453 moveto
  /CenturySchL-Roma 3.86523438 output-scale div selectfont
  0.6146 0.0000 0.0000 /space
  1 print_glyphs

We don't have any text, but lilypond still unnecessarily emits a
`/space' glyph (and consequently embeds the New Centry Schoolbook
font).

This is essentially harmless, but IMHO it should be fixed eventually.
I suspect that the header formatting Scheme code misses some checks to
test whether we actually have input.


    Werner