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().