Allow generic server deserialization for querying

See http://stackoverflow.com/questions/26037793/hazelcast-queries-on-server-without-classes-being-present
This change adds the capability requested in the Stackoverflow question. This is a major change with architecture implications so please review carefully.
A good description of the new functionality can be found on the new interface AttributeAccessible.
The unit test AttributeAccessibleTest tests the feature for querying and indexing.
There should be documentation for this in the manual, maybe under topic 12.6. Tell me if I should write something and in which format it should be (html, markdown, ...).
What happens when:
- attributeName is null
- there is no attribute for a given attributeName
- the attribute for the given attributeName is null
- the attribute for a given attributeName is a primitive

Does it also deal correctly with e.g. private fields?