Disable the type-ahead search in the connection editor, the
number of items, and their positional stability means that
a search feature isn't warranted.
As a precaution, also check the success of
gtk_tree_selection_get_selected() to avoid crashes.
https://bugzilla.gnome.org/show_bug.cgi?id=693685
This code is fairly independent of the rest, and we don't want
net-device-wifi.c to become too massive and unmaintainable.
The code in connection-editor/ is fairly similar to
nm-connection-editor, with some simplification because we
currently only edit wireless connections.
The code in wireless-security/ is almost a straight copy
of the same code in nm-connection-editor, with some changes
to the .ui files to make them fit better in the new design.
