Changing the look of the GtkTreeView

[Arnaud Charlet <charlet ACT-Europe FR>]

I was wondering how you can change the look and feel of the
GtkTreeView. In particular, I'd like to use the standard
+/- icons to open/close a tree, have lines drawn vertically between
items, and change the rectangles by custom icons. All the kind of basic
things that was easy to do with Ctree in short.

How is this possible with the TreeView ?

Subsidiary question: why has it been decided to use this new default
look and feel (strange rectangles, and no links between items) ? Seems
less user friendly and less intuitive than the Ctree default to me, but
if there are good reasons, I'd be interested to know about them.

Arno