[gtkmm] Build: Require the latest cairomm.

[Murray Cumming <murrayc src gnome org>]

commit e941498d03b1f9bf9050f35c19fe04d3afa2bfb1
Author: Murray Cumming <murrayc murrayc com>
Date:   Thu Jan 12 12:16:14 2017 +0100

    Build: Require the latest cairomm.
    
    Because we use the new Cairo::make_refptr_for_instance() method as
    of this commit:
    https://git.gnome.org/browse/gtkmm/commit/?id=b1bd48a09292020cf7042c2802fe8275760ddba4
    We usually get cairomm implicitly via pangomm, but pangomm does not
    need to use that method.

 configure.ac |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 97f1bcc..209626d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -94,7 +94,8 @@ AS_IF([test "x$enable_static" = xyes],
 
 # gdkmm really does need GTK+, because part of Gdk::DragContext is in GTK+.
 # The extra gdk-pixbuf-2.0 check is because gdkmm requires a newer gdk-pixbuf than gtk+-4.0 requires.
-AC_SUBST([GDKMM_MODULES], ['giomm-2.52 >= 2.49.1 pangomm-2.42 >= 2.38.2 gtk+-4.0 >= 3.89.2 gdk-pixbuf-2.0 >= 
2.35.5'])
+# TODO: Remove the mention of cairomm once pangomm needs to depend on such a new version.
+AC_SUBST([GDKMM_MODULES], ['giomm-2.52 >= 2.49.1 pangomm-2.42 >= 2.38.2 cairomm-1.16 >= 1.15.3 gtk+-4.0 >= 
3.89.2 gdk-pixbuf-2.0 >= 2.35.5'])
 
 AS_IF([test "x$gtkmm_host_windows" = xyes],
       [GTKMM_MODULES=$GDKMM_MODULES],