Write log to stderr

Be consistent with python's default behavior and play nice with CGI.

logging

@@ -39,7 +39,7 @@ handlers = console,file
 # Console handler
 class = StreamHandler
 level = INFO
-args = (sys.stdout,)
+args = (sys.stderr,)
 formatter = simple
 
 [handler_file]

radicale/log.py

@@ -55,9 +55,9 @@ def start(name="radicale", filename=None, debug=False):
         # Default configuration, standard output
         if filename:
             logger.warning(
-                "Logging configuration file '%s' not found, using stdout." %
+                "Logging configuration file '%s' not found, using stderr." %
                 filename)
-        handler = logging.StreamHandler(sys.stdout)
+        handler = logging.StreamHandler(sys.stderr)
         handler.setFormatter(logging.Formatter("%(message)s"))
         logger.addHandler(handler)
     if debug: