update README with info on new logging scheme

Signed-off-by: Andy Green <andy.green@linaro.org>

README-test-server

@@ -237,13 +237,37 @@ export http_proxy=myproxy.com:3128
 libwebsockets-test-client someserver.com
 
 
+debug logging
+-------------
+
+By default logging of severity "warn" or "err" is enabled to stderr.
+
+Again by default other logging is comiled in but disabled from printing.
+
+If you want to eliminate the debug logging below warn in severity, use the
+--disable-debug configure option to have it removed from the code by the
+preprocesser.
+
+If you want to see more detailed debug logs, you can control a bitfield to
+select which logs types may print using the lws_set_log_level() api, in the
+test apps you can use -d <number> to control this.  The types of logging
+available are (OR together the numbers to select multiple)
+
+ 1   ERR
+ 2   WARN
+ 4   INFO
+ 8   DEBUG
+ 16  PARSER
+ 32  HEADER
+ 64  EXTENSION
+ 128 CLIENT
+
+
 Websocket version supported
 ---------------------------
 
-The websocket client code is 04 and 05 version, the server
-supports 00/76 in text mode and 04 and 05 dynamically
-per-connection depending on the version of the
-client / browser.
+The final IETF standard is supported along with various older ones that will
+be removed at some point, -76, -04 and -05.
 
 
 External Polling Loop support