[gtk+/xi2-for-master] Document GDK_MULTIDEVICE_SAFE

[Matthias Clasen <matthiasc src gnome org>]

commit 8f909c148d2f8f1db133ddeff90a68c7a8460fcd
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri May 21 14:09:49 2010 -0400

    Document GDK_MULTIDEVICE_SAFE

 docs/reference/gtk/compiling.sgml |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/docs/reference/gtk/compiling.sgml b/docs/reference/gtk/compiling.sgml
index a9a3632..f33cffa 100644
--- a/docs/reference/gtk/compiling.sgml
+++ b/docs/reference/gtk/compiling.sgml
@@ -63,6 +63,13 @@ symbol GDK_MULTIHEAD_SAFE by using the command line option
 </para>
 
 <para>
+Similarly, if you want to make sure that your program doesn't use any
+functions which may be problematic in a multidevice setting, you can
+define the preprocessor symbol GDK_MULTIDEVICE_SAFE by using the command
+line option <literal>-DGTK_MULTIDEVICE_SAFE=1</literal>.
+</para>
+
+<para>
 The recommended way of using GTK+ has always been to only include the
 toplevel headers <filename>gtk.h</filename>, <filename>gdk.h</filename>, 
 <filename>gdk-pixbuf.h</filename>.