* glib/ClassInitializerAttribute.cs : new attr for identifying type.
inialization methods to be run by RegisterGType.
* glib/Makefile.am : add file.
* glib/Object.cs : add private method to invoke ClassInitializers.
* gtk/glue/widget.c : some new glue for binding registration.
* gtk/BindingAttribute.cs : new attr for registering key bindings.
* gtk/Makefile.am : add file.
* gtk/Widget.custom : add ClassInitializer method to scan types
for [Binding] and register key bindings.
svn path=/trunk/gtk-sharp/; revision=38074
