Add proxy support for WebSocket connections

Configuration for Socket.IO has been refactored to support proxies and replace ambiguous property names:

• Added API property socketioPath to /configuration/
• Added property socketio.proxy-path
• Removed property security.ssl
• Renamed properties:
  • socketio.ip -> socketio.bind-address
  • security.keystore -> socketio.ssl.jks-file
  • security.storepass -> socketio.ssl.jks-password

The default port to bind to has been changed from 10443 to 8090 since SSL is not enabled by default. There is enough room (8081-8089) for additional severs (e.g. grunt run) in development environments.