Add code for blurring (original code from Unico, copyright fine for Gtk+)

gtk/gtkcairoblurprivate.h

@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2012 Canonical Ltd
+ *
+ * This  library is free  software; you can  redistribute it and/or
+ * modify it  under  the terms  of the  GNU Lesser  General  Public
+ * License  as published  by the Free  Software  Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed  in the hope that it will be useful,
+ * but  WITHOUT ANY WARRANTY; without even  the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License  along  with  this library;  if not,  write to  the Free
+ * Software Foundation, Inc., 51  Franklin St, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ * Authored by Andrea Cimitan <andrea.cimitan@canonical.com>
+ * Original code from Mirco Mueller <mirco.mueller@canonical.com>
+ *
+ */
+
+#ifndef _GTK_CAIRO_BLUR_H
+#define _GTK_CAIRO_BLUR_H
+
+#include <glib.h>
+#include <cairo.h>
+
+G_BEGIN_DECLS
+
+void            _gtk_cairo_blur_surface (cairo_surface_t* surface,
+                                         guint            radius);
+
+G_END_DECLS
+
+#endif /* _GTK_CAIRO_BLUR_H */