Fix #53 ObjectLiteral(s) are not supported yet

The following template now works:
```
# template hello(config)
    <div class="msg">
        Hello {config.name}!
    </div>
# /template

# template main()
    <#hello config="{{name: 'World'}}"/>
# /template

// display the template in the #output div
main().render("output");
```