Driver: Fix noisy errors, UDP message send failure spam.

Closes #26.

This will also prevent a full reconnect failure from endlessly spamming attempts and error logs. I'll follow this up by looking into decent reconnection strategies, although sadly these won't be configurable until the next semver break due to an oversight on my part.

src/driver/tasks/mixer.rs

@@ -228,21 +228,31 @@ impl Mixer {
             // event failure? rebuild interconnect.
             // ws or udp failure? full connect
             // (soft reconnect is covered by the ws task.)
+            //
+            // in both cases, send failure is fatal,
+            // but will only occur on disconnect.
+            // expecting this is fairly noisy, so exit silently.
             if events_failure {
                 self.prevent_events = true;
-                self.interconnect
+                let sent = self
+                    .interconnect
                     .core
-                    .send(CoreMessage::RebuildInterconnect)
-                    .expect("FATAL: No way to rebuild driver core from mixer.");
+                    .send(CoreMessage::RebuildInterconnect);
                 events_failure = false;
+
+                if sent.is_err() {
+                    break;
+                }
             }
 
             if conn_failure {
-                self.interconnect
-                    .core
-                    .send(CoreMessage::FullReconnect)
-                    .expect("FATAL: No way to rebuild driver core from mixer.");
+                self.conn_active = None;
+                let sent = self.interconnect.core.send(CoreMessage::FullReconnect);
                 conn_failure = false;
+
+                if sent.is_err() {
+                    break;
+                }
             }
         }
     }