Add support for deleting PropertyDefinitions to FuelSDK. #CIQ-1772
Added Support for setting RetrieveOptions in Retrieve requests. See https://help.exacttarget.com/en/technical_library/web_service_guide/objects/retrieveoptions/
Updated DataExtension examples with RetrieveOptions example.
Merge pull request #34 from CommandIQ/master

Added RetrieveOptions support for RetreiveRequest in ET_Get. Added support for delete operations to ET_Configure.