Add 2 new events to enable logger pluginization: StartLog and EndLog

EVENTS.txt

@@ -617,3 +617,14 @@ EndInlineScriptElement: After a <script...> element is written
 - $action
 - $code
 - $type
+
+StartLog: Before writing to the logs
+- &$priority
+- &$msg
+- &$filename
+
+EndLog: After writing to the logs
+- $priority
+- $msg
+- $filename
+

lib/util.php

@@ -1070,6 +1070,7 @@ function common_request_id()
 
 function common_log($priority, $msg, $filename=null)
 {
+    if(Event::handle('StartLog', array(&$priority, &$msg, &$filename))){
         $msg = '[' . common_request_id() . '] ' . $msg;
         $logfile = common_config('site', 'logfile');
         if ($logfile) {
@@ -1083,6 +1084,8 @@ function common_log($priority, $msg, $filename=null)
             common_ensure_syslog();
             syslog($priority, $msg);
         }
+        Event::handle('EndLog', array($priority, $msg, $filename));
+    }
 }
 
 function common_debug($msg, $filename=null)