[glibmm] Fix the build after previous commit

[Murray Cumming <murrayc src gnome org>]

commit 3aee3aaacac0cbf2c5372071a82cdc3cb4753d52
Author: Murray Cumming <murrayc murrayc com>
Date:   Tue Sep 17 11:15:09 2013 +0200

    Fix the build after previous commit

 glib/src/variant.ccg |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)
---
diff --git a/glib/src/variant.ccg b/glib/src/variant.ccg
index 7b69c2c..bfdff9f 100644
--- a/glib/src/variant.ccg
+++ b/glib/src/variant.ccg
@@ -20,6 +20,19 @@
 #include <glib.h>
 #include <iostream>
 
+extern "C"
+{
+
+//This is hack to workaround this problem in glib:
+//  https://bugzilla.gnome.org/show_bug.cgi?id=708212
+//We really should not define a g_* symbol outside of glib:
+GQuark g_variant_parse_error_quark()
+{
+  return g_variant_parser_get_error_quark();
+}
+
+} //extern C
+
 namespace Glib
 {