Clean-up of skins/common/IEFixes.js

- Wrap script code in an IIFE.
- Create scope-local bindings for global vars.
- Use strict comparisons.
- Use single var statement to declare variables.

Change-Id: I1ee94b184f5bb2355d01fae554c50ef314147298
Merge "Clean-up of skins/common/IEFixes.js"