selecting multiple entries from GtkTreeView/GtkTreeModel/GtkTreeStore

[Gorshkov <listsubscriptions oghma on ca>]

I've looked in the docs, and I keep going around and around in circles - 
but I can't for the life of me figure out how to set a 
TreeView/TreeModel/TreeStore to allow for the selection of multiple entries.

I'm pretty sure I'm missing something simple and obvious, but I can't 
for the life of me find it anywhere .... help, somebody?