0030849: Add a method to extract a diff of 2 json objects

diff --git a/web/org.openbravo.mobile.core/source/utils/ob-utilities.js b/web/org.openbravo.mobile.core/source/utils/ob-utilities.js
--- a/web/org.openbravo.mobile.core/source/utils/ob-utilities.js
+++ b/web/org.openbravo.mobile.core/source/utils/ob-utilities.js
@@ -821,27 +821,39 @@
           if (obj1[key] !== obj2[key]) {
             result[key] = [obj2[key], obj1[key]];
           }
-        } else {
-          if (obj2[key].constructor && obj2[key].constructor === Array && obj1[key].constructor && obj1[key] === Array && obj2[key].length !== 0) {
+        } else if ($.isArray(obj1[key])) {
+          if (!$.isArray(obj2[key]) || obj1[key].length != obj2[key].length) {
+            result[key] = [obj2[key], obj1[key]];
+          } else {
             var preResult = OB.UTIL.diffJson(obj1[key], obj2[key]);
             if (JSON.stringify(preResult) !== '{}') {
               result[key] = preResult;
             }
-            continue;
           }
-          if (typeof obj2[key] === 'object' && typeof obj1[key] === 'object' && $.isEmptyObject(obj2[key]) === false) {
+        } else if ($.isPlainObject(obj1[key])) {
+          if (!$.isPlainObject(obj2[key])) {
+            result[key] = [obj2[key], obj1[key]];
+          } else {
             var preResult2 = OB.UTIL.diffJson(obj1[key], obj2[key]);
             if (JSON.stringify(preResult2) !== '{}') {
               result[key] = preResult2;
             }
-            continue;
           }
-          if (obj2[key] !== obj1[key] && obj2[key].length !== 0 && $.isEmptyObject(obj2[key]) === false) {
-            result[key] = [obj2[key], obj1[key]];
-          }
+        } else if (obj2[key] !== obj1[key]) {
+          result[key] = [obj2[key], obj1[key]];
         }
       }
     }
+
+    // find any properties which are in obj2 but not in obj1
+    for (var key in obj2) {
+      if (obj2.hasOwnProperty(key) && !obj1.hasOwnProperty(key)) {
+        if (obj2[key] !== undefined && obj2[key] !== null) {
+          result[key] = [obj2[key], null];
+        }
+      }
+    }
+
     return result;
   };