Include our newline atomically

Sometimes clashing log entries would print on the same line, likely due
to some sort of race condition in Python's print() built-in.

Instead, add a newline to our actual message and print without an end
character. This ensures atomic printing of our log messages.

daemon-common/log.py

@@ -146,7 +146,7 @@ class Logger(object):
         if self.config["stdout_logging"]:
             # Assemble output string
             output = colour + prompt + endc + date + prefix + message
-            print(output)
+            print(output + "\n", end="")
 
         # Log to file
         if self.config["file_logging"]: