reduced complex function to smaller ones

lib/log4js.js

@@ -111,21 +111,29 @@ function addAppender () {
   }
   
   args.forEach(function(category) {
-    if (!appenders[category]) {
+    addAppenderToCategory(appender, category);
-      appenders[category] = [];
-    }
-    appenders[category].push(appender);
     
     if (category === ALL_CATEGORIES) {
+      addAppenderToAllLoggers(appender);
+    } else if (loggers[category]) {
+      loggers[category].addListener("log", appender);
+    }
+  });
+}
+
+function addAppenderToAllLoggers(appender) {
   for (var logger in loggers) {
     if (loggers.hasOwnProperty(logger)) {
       loggers[logger].addListener("log", appender);
     }
   }
-    } else if (loggers[category]) {
-      loggers[category].addListener("log", appender);
 }
-  });
+
+function addAppenderToCategory(appender, category) {
+  if (!appenders[category]) {
+    appenders[category] = [];
+  }
+  appenders[category].push(appender);
 }
 
 function clearAppenders () {