[tomboy] Require Mono 1.9.1 to *build* Tomboy. Fixes bug #573923.

[Sanford Armstrong <sharm src gnome org>]

commit 71efea5aa63dd7eac3653ef9bda0c304267a91d5
Author: Sandy Armstrong <sanfordarmstrong gmail com>
Date:   Mon May 25 10:22:59 2009 -0700

    Require Mono 1.9.1 to *build* Tomboy. Fixes bug #573923.
    
    Note that this is just a build requirement; for now, Tomboy should still
    run on older versions of Mono.
---
 configure.in |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/configure.in b/configure.in
index b2dbb53..5e3f712 100644
--- a/configure.in
+++ b/configure.in
@@ -41,6 +41,12 @@ if test "x$GMCS" = "x" ; then
 fi
 
 #
+# Check Mono version
+#
+MONO_MINIMUM_VERSION=1.9.1
+PKG_CHECK_MODULES(MONO, mono >= $MONO_MINIMUM_VERSION)
+
+#
 # Gdk and Atk are needed for libtrayicon
 #
 GDK20_MINIMUM_VERSION=2.6.0