HSEARCH-704 Refactoring code

- Dropping the 's' in ObjectsLoader and its implementations
- Javadoc fixes
- Test refactoring
- Adding toString
HSEARCH-704 Adding test case for n+1 query problem
HSEARCH-704 Changing contract of ObjectInitializer. In particular the initialized objects are not stored in a LinkedHashMap.
HSEARCH-1119 Making object lookup and database retrieval methods configurable
HSEARCH-1448 Making sure that a potential proxy gets unproxied before accessed/returned