Steven Thomas Smith authored and Frank Schima committed 1ffcd9f898a
macos-vpn-server: Submission of macOS-native VPN (L2TP-IPSec-PSK) Server
* Configures native VPN Server on macOS
* Based on deprecated VPN Server in macOS Server.app
* MacPorts-specific launchdaemon for vpnd, Keychain PSK
* Reference: https://developer.apple.com/support/macos-server/macOS-Server-Service-Migration-Guide.pdf