Fixing issues with strict mode

closes #45

lib/utils.js

@@ -145,15 +145,15 @@ function forEach(obj, fn) {
   }
 
   // Check if obj is array-like
-  var isArray = obj.constructor === Array || typeof obj.callee === 'function';
+  var isArrayLike = isArray(obj) || (typeof obj === 'object' && !isNaN(obj.length));
 
   // Force an array if not already something iterable
-  if (typeof obj !== 'object' && !isArray) {
+  if (typeof obj !== 'object' && !isArrayLike) {
     obj = [obj];
   }
 
   // Iterate over array values
-  if (isArray) {
+  if (isArrayLike) {
     for (var i=0, l=obj.length; i<l; i++) {
       fn.call(null, obj[i], i, obj);
     }
@@ -210,4 +210,4 @@ module.exports = {
   forEach: forEach,
   merge: merge,
   trim: trim
-};
+};