better handling for logging to stdout

* disable stdout buffering when logging to stdout
* add 'log_to_syslog' parameter in configuration file to enable/disable
logging to syslog
* add 'log_to_stdout' parameter in configuration file to enable/disable
logging to stdout

slight clean-up and reformatting also (thanks to clang-format new
version)

src/lib/rfc3161.c

@@ -319,8 +319,9 @@ end:
         ret = 200;
         break;
     case TS_STATUS_GRANTED_WITH_MODS:
-        uts_logger(ct, LOG_NOTICE, "timestamp request granted with "
-                                   "modification",
+        uts_logger(ct, LOG_NOTICE,
+                   "timestamp request granted with "
+                   "modification",
                    *serial_id);
         ret = 200;
         break;