Fix invalid XML from the CLI xml reporter (#217)

* Remove javascriptExecutionTree from the xml output
* Change JSON structure for offenders classified by url
* Remove special chars from XML output

lib/offendersHelpers.js

@@ -207,24 +207,31 @@ var OffendersHelpers = function() {
     };
 
     this.orderByFile = function(offenders) {
-        var byFile = {};
+        var byFileObj = {};
 
         offenders.forEach(function(offender) {
             var file = offender.file || 'Inline CSS';
             delete offender.file;
 
-            if (!byFile[file]) {
-                byFile[file] = {
+            if (!byFileObj[file]) {
+                byFileObj[file] = {
+                    url: file,
                     count: 0,
                     offenders: []
                 };
             }
 
-            byFile[file].count ++;
-            byFile[file].offenders.push(offender);
+            byFileObj[file].count ++;
+            byFileObj[file].offenders.push(offender);
         });
 
-        return {byFile: byFile};
+        // Transform object into array
+        var byFileArray = [];
+        for (var file in byFileObj) {
+            byFileArray.push(byFileObj[file]);
+        }
+
+        return {byFile: byFileArray};
     };
 
 };