* sample: Update samples to new Glade.Widget.
* glade/WidgetAttribute.cs: Moved the old GladeWidgetattribute
here. Now its called `Glade.WidgetAttribute'.
* glade/GladeWidgetAttribute.cs: Removed
* glib/Idle.cs: Do not allow Idle class to be instantiated.
svn path=/trunk/gtk-sharp/; revision=12554