We also remove support for WiMAX (now unsupported by NetworkManager),
and InfiniBand (Enterprise feature), and the use of
the deprecated NM_SETTING_WIRELESS_SEC property.
With help from network-manager-applet patches by Jiří Klimeš and
Dan Winship.
https://bugzilla.gnome.org/show_bug.cgi?id=765910
Since LIBDIR of gnome-control-center and the VPN plugins aren't
necessarily the same, use the paths as specified by the VPN plugins and
only reconstruct the path if it is not absolute or we fail to load the
plugin.
Patch from Debian package, by Michael Biebl <biebl@debian.org>
https://bugzilla.gnome.org/show_bug.cgi?id=764509
Unfortunately, the VPN plugins provide their own .ui files for their
editor pages, so we can't make them look competely GNOME-3-ish. But
the code does try to fix them up a little bit by realigning the
labels.
vpn-helpers.[ch] is nearly identical to network-manager-applet's,
but eventually this code will move into libnm-gtk.
https://bugzilla.gnome.org/show_bug.cgi?id=691285
