* Makefile.am: reenable samples.
* sample/Actions.cs: s/Item/MenuItem, Item is dead.
* sample/NativeInstantiationTest.cs: fix dllimport, still crashes.
* sample/PolarFixed.cs: Fix size negotiation API usage, still crashes.
* sample/TreeModelDemo.cs: add ItemPrevious, still crashes.
* sample/Makefile.am: comment out some samples that don't build.
* generator/*.cs: implement the interfaces on the adapters too.
Generate an Implementor interface for users which exposes the
methods to implement. Register based on the Implementor sub-iface.
* gtk/*Adapter.custom: custom implementations for the custom
interface members.
* gtk/TreeIter.custom: make UserData public.
* sample/TreeModelDemo.cs: sample for implementing a TreeModel
interface.
svn path=/trunk/gtk-sharp/; revision=86753