Some fixes: Mainly added PHP 5.3 support.

This pull request groups some fixes/changes i've made: 

- typo in readme.md
- Added readme.md to the `Redirector` folder itself, so it can be read from within Bolt (this will require some editing, though)
- Added PHP 5.3 support. On 5.3 the extension threw some "Using $this when not in object context" Exceptions. This is because support for `$this` in closures wasn't added until 5.4. 

Before I forget to mention: The extension works great! Especially happy that you can so easily do things like this: 

```yml
pages:
        from: '{slug:any}.{ext:commonextensions}'
        to: 'page/{slug}'
```

Great stuff! Happy to include this with Bolt, because quite a few people have asked for a better solution than the old 'NiceUrls'. :-)