Merge pull request #893 from KuroGuo/dev

fix getContainedComponents in IE 11

src/directives/if.js

@@ -90,7 +90,7 @@ module.exports = {
       var next
       while (next !== end) {
         next = cur.nextSibling
-        if (cur.contains(c.$el)) {
+        if (cur.contains && cur.contains(c.$el)) {
           return true
         }
         cur = next