retrieving key presses

[Richard Harvey Chapman <hchapman 3gfp com>]

I'd like to retrieve any keys that may have been pressed when a user
selected a GtkTreeItem.  I'd like to add a new type of selection to
GtkTree that behaves more like the windows style of selection.  Namely:
single_selection normally unless shift or control are pressed along with
the selection.  If my application is going to be well received, the
selection mechanism needs to mirror what is already "familiar" to my
customers who are all used to Windows apps.

R.