is there a way to suppress repeated time signatures (analogous to chordChanges)

[Kieren MacMillan]

Hello all,

Consider the following snippet:

\version "2.17.29"

global = {
  \time 3/4
  s4*3
}
notes = {
  c'1.
}

\score {
  \new Staff \repeat "unfold" 3 { << \global \notes >> }
}

This is contrived, of course, but I run into it a lot when I “stitch together” 
pre-existing variables (which include time signatures) into a medley, etc.
Is there a global setting that I can use — analogous to the chordChanges switch 
in ChordNames — so that time signatures only appear if they change?

Thanks,
Kieren.