Client|Fixed: ServerLink cannot be constructed before main()

It requires the existence of a de::App.
libdeng2: Moved the isHostLocal test to Address (from Socket)

A more suitable place for this test.
Fixed: Client connects to server

Corrected problems the new ServerLink was experiencing when connecting
to a client.

All local IP addresses are now converted to "localhost" so that a
server on the local host isn't listed multiple times (e.g., as
"localhost" and 10.0.1.1).