IE8 showing error "Object doesn't support this property or method" for aui-form-validator.js file

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.0.x, master, master-deprecated
• Fix Version/s: 2.0.x, master, master-deprecated, 3.0.x, 2.0.0.79-deprecated, 3.1.x
• Component/s: Form Validator
• Labels: None
• Fix Priority: 3
• Git Pull Request: https://github.com/mairatma/alloy-ui/pull/339

Reproduction steps:
1. Set a VM for IE 8
2. Go to the Github alloy-ui repository
3. Go to demos/form-validator
4.Open the index.html file in the editor
5.Change showAllMessages to "false" value (Line:173)
6.Run the file in the IE 8 and open the developer tools window
7. Set a breakpoint at Line:877
8. Refresh the page

Actual result: "Object doesn't support this property or method" error for aui-form-validator.js file