Display score title differently on odd or even pages

[Jay Anderson]

Is it possible to check whether the page is odd or even in creating
the score title markup. I'm setting a group of hymns and I'd like the
hymn number on the outside of the page.

Looking at titling-init.ly it gets two different page properties
page:page-number and page:page-number-string. Here's a test:

\version "2.15.30"

#(define-markup-command (print-page layout props) ()
  (let ((page (chain-assoc-get 'page:page-number-string props "xxx")))
    (interpret-markup layout props #{ \markup { $page } #})))

\paper
{
  oddHeaderMarkup = \markup { \print-page }
  oddFooterMarkup = \markup { \print-page }
  scoreTitleMarkup = \markup { \line {"title" \print-page } }
}

\score { \new Staff \relative c' { c1 } }
\pageBreak
\score { \new Staff \relative c' { c1 } }
\pageBreak
\score { \new Staff \relative c' { c1 } }

Unfortunately this returns the passed in default instead of the page
number for the title. Is there another way to do this? Or is the page
number known too late to do something like this?

-----Jay