"reverting" \RemoveEmptyStaves

[Kieren MacMillan]

Hello all!

What's the best way (in >= 2.14) to override a \RemoveEmptyStaves command from 
a context defined in an included file?

In order to get this particular score out the door ASAP, I've "pre-redefined" 
the function this way:

    RemoveEmptyStaves = \with { \override VerticalAxisGroup #'remove-first = 
##f }
    \include "../../_include/paper/pianovocal_letter.ly"  %% this contains 
\layout { \context { \Staff \RemoveEmptyStaves } }

This hack works in my current pinch, since I happened to need to set 
#'remove-first anyway.
However, I'd like to know the "cleaner" way, if there is one.

Thanks,
Kieren.