Initial Hotplug support (#8)

This allows to dynamically add clients when an event is received from an unknown IP address.

The user is asked to confirm any unknown connection from new clients.

Currently the back-ends for event producing and consuming are not yet notified, so events will not be received and sent to the newly created clients.

src/backend/consumer/wlroots.rs

@@ -69,7 +69,7 @@ impl App {
             (_, _, Ok(fake_input)) => {
                 fake_input.authenticate(
                     "lan-mouse".into(),
-                    "Allow remote clients to control this devices".into(),
+                    "Allow remote clients to control this device".into(),
                 );
                 VirtualInputManager::Kde { fake_input }
             }