Helps with automation. Install the VPN configuration before persisting a
profile, so that the 1:1 reference with OS settings is maintained.
Likewise, uninstall the VPN configuration after removing a profile.
This before-save hook also resolves a problem with multiple imports,
where multiple VPN permission alerts coalesce if no VPN configuration is
installed. Now the first import waits for the permission synchronously.
Fixes#618