Background DocumentObjectBinder

The HST DocumentObjectBinder extends the Solrj DocumentObjectBinder in order to

1. Be able to index and bind different bean/pojo classes instead of a single type of class
2. Inject some default mandatory indexing fields, like the pojo's fully qualified class name, the class hierarchy, the path hierarchy, etc
3. To be able to index Compound bean structures
4. To improve annotation scanning, add extra annotations, and avoid modifying the accessibility of class members (which is not allowed in security enabled containers)