* gtk/Makefile.am : add new file.
* gtk/glue/makefile.win32 : add missing file.
* gtk/NodeCellDataFunc.cs : new callback delegate type and marshaler
for NodeStore tree views using GtkTreeCellDataFuncs.
* gtk/NodeStore.cs : add internal GetNode overload by TreeIter.
* gtk/NodeView.cs : add AppendColumn overload that uses data funcs.
* gtk/TreeViewColumn.custom : manual implementation for SetCellDataFunc
to support both TreeIter and ITreeNode models. We need to hold a ref
to a delegate for each cell renderer on a column. [Fixes#63062]
* sample/NodeViewDemo.cs : use a NodeCellDataFunc for one of the
cell renderers in the tree.
svn path=/trunk/gtk-sharp/; revision=37904
