Extend the feature by also providing a complementary "include" policy,
i.e. activate the VPN _only_ on the specified networks. "Trusted
networks" was only providing the "exclude" counterpart, i.e. _except_
the specified networks.
Closes#119
The VPNConfiguration parameter is opaque and tightly coupled to
TunnelKit. Connecting to a Profile makes infinitely more sense, beyond
simplifying the VPNManager class. Configuration building is fully
delegated to the strategy (as it has to be).
- VPNManager takes Profile and produces VPNConfigurationParameters
- VPNManagerStrategy takes VPNConfigurationParameters (abstract)
- TunnelKitVPNManagerStrategy takes VPNConfigurationParameters and
produces TunnelKitVPNConfiguration internally