\noSpace macro?

[Kieren MacMillan]

Hi all,

In addition to the \omit and \hide macros (which, by the way, are very nice; 
thanks!), I would love a \noSpace macro, which says "ignore this grob when 
calculating spacing, but print it anyway".

Looking at the docs, I would have thought this would work:

\version "2.17.19"
\language "english"

piano_global = { \key d \major }

piano_notes_upper = \relative d'' {
  <d d'>4-. r <e e'>-. r   | % 21
  <fs fs'>2.\fermata fs,4   | % 22
}

whiteFFMarkup = \markup { \whiteout \pad-markup #0.5 \dynamic ff}
whiteFF = #(make-dynamic-script whiteFFMarkup)
piano_dynamics = {
  s2\ff s\ff   | % 21
  s2.-\tweak #'X-offset #-3 -\tweak #'extra-spacing-width #'(+inf.0 . -inf.0) 
-\tweak #'extra-spacing-height #'(-inf.0 . +inf.0) \whiteFF s4\p   | % 22
}

piano_notes_lower = \relative d, {
  \clef bass
  <d d'>4-. r <e e'>-. r   | % 21
  <fs fs'>2.\fermata r4   | % 22
}

\score {
  \new PianoStaff <<
    \new Staff << \piano_global \piano_notes_upper >>
    \new Dynamics \piano_dynamics
    \new Staff << \piano_global \piano_notes_lower >>
  >>
}

But it doesn't.

I'm trying to get this "Henle piano stylesheet" project done so that I can 
share it with the 'Pond.
I want to be able to duplicate the edition I have as closely as possible, so 
any help would be appreciated.

Thanks,
Kieren.