Global code ovehaul - remove CAS and other, add 15 minute greet check

- Remove CAS, as it no longer works for us
- Remove other checks
- Implement 15 minute greet timeout check
- Fix chat logos
- Ditch thirdparty logger, use stdlib log facility wrapper for logging

internal/moon/exitCode_unix.go

@@ -0,0 +1,28 @@
+//go:build !windows
+
+package moon
+
+import (
+	"os"
+	"syscall"
+)
+
+// exitCodeFor maps one terminating signal to the status a stopped process
+// should carry: 128 + the signal's number on Unix.
+func exitCodeFor(s os.Signal) int {
+	switch s {
+	case syscall.SIGINT:
+		return signalExitBase + 2
+
+	case syscall.SIGTERM:
+		return signalExitBase + 15
+
+	case syscall.SIGQUIT:
+		return signalExitBase + 3
+
+	default:
+		return 0
+	}
+}
+
+/* vim: set ft=go noet ai ts=4 sw=4 sts=4: */