fixed missing space between log data elements

lib/layouts.js

@@ -44,6 +44,9 @@ function formatLogData(logData) {
     }
 
     data.forEach(function (item) {
+        if (output) {
+            output += ' ';
+        }
         if (item && item.stack) {
             output += item.stack;
         } else {

test/layouts.js

@@ -57,14 +57,14 @@ vows.describe('log4js layouts').addBatch({
         },
         'should support the console.log format for the message' : function(layout) {
               assert.equal(layout({
-                  data: ["thing %d", 1]
+                  data: ["thing %d", 1, "cheese"]
                 , startTime: new Date(2010, 11, 5, 14, 18, 30, 45)
                 , categoryName: "cheese"
                 , level : {
                     colour: "green"
                   , toString: function() { return "ERROR"; }
                 }
-              }), "thing 1");
+              }), "thing 1 'cheese'");
           },
         'should output the first item even if it is not a string': function(layout) {
             assert.equal(layout({