Appends a new row to tree_store. If parent is non-NULL, then it will append the
new row after the last child of parent, otherwise it will append a row to
the top level. iter will be changed to point to this new row. The row will
be empty after this function is called. To fill in values, you need to call
gtk_tree_store_set() or gtk_tree_store_set_value().
Appends a new row to tree_store. If parent is non-NULL, then it will append the new row after the last child of parent, otherwise it will append a row to the top level. iter will be changed to point to this new row. The row will be empty after this function is called. To fill in values, you need to call gtk_tree_store_set() or gtk_tree_store_set_value().