Merge branch '21_enable_debugging'

diff --cc include/event2/event.h
index fae5bb87a8acdb114f583117955acd51c0650165,415116ed3cea52a0002de7f171d8a096b4ac6f8e..b86bcc0c1a1b48705f4d01b4ec0224bd485a6f0e
--- 1/include/event2/event.h
--- 2/include/event2/event.h
+++ b/include/event2/event.h
@@@ -638,8 -310,28 +638,27 @@@ typedef void (*event_fatal_cb)(int err)
   Libevent will (almost) always log an _EVENT_LOG_ERR message before calling
   this function; look at the last log message to see why Libevent has died.
   */
 -typedef void (*event_fatal_cb)(int err);
  void event_set_fatal_callback(event_fatal_cb cb);
  
+ #define EVENT_DBG_ALL 0xffffffffu
+ #define EVENT_DBG_NONE 0
+ 
+ /**
+  Turn on debugging logs and have them sent to the default log handler.
+ 
+  This is a global setting; if you are going to call it, you must call this
+  before any calls that create an event-base.  You must call it before any
+  multithreaded use of Libevent.
+ 
+  Debug logs are verbose.
+ 
+  @param which Controls which debug messages are turned on.  This option is
+    unused for now; for forward compatibility, you must pass in the constant
+    "EVENT_DBG_ALL" to turn debugging logs on, or "EVENT_DBG_NONE" to turn
+    debugging logs off.
+  */
+ void event_enable_debug_logging(ev_uint32_t which);
+ 
  /**
    Associate a different event base with an event.
  

diff --cc log.c
Simple merge