Fixes #528 - Add support for As.EXISTING_PROPERTY inclusion mechanism
Fixes #528 - Added another set of unit tests for EXISTING_PROPERTY
serialization and deserialization
fixes #528 - Code refactoring to eliminate duplicate code between
inclusion mechanism EXISTING_PROPERTY and PROPERTY via inheritance.
Merge pull request #581 from fleebytes/master

Fixes #528 - Add support for As.EXISTING_PROPERTY inclusion mechanism