Refactoring of the methods that save objects to the database.
EnquiryManager:createEnquiry -> EnquiryManager:saveEnquiry
EnquiryManager:answerEnquiry -> EnquiryManager:saveAnswer
Changed the "serialization" of the about field in Enquiry to JSON format.
Removed the aboutDefinition field, about field is used to save the definition.
The "serialization" is not performed in an Enquiry method anymore, but in the listener and repository method.
Added the postPersist event to the listener so it can revert the about field to point to an object after persisted, so any call to getAbout in any Enquiry object returns an actual object and not the definition.
Make the user parameter required in EnquiryManager:saveEnquiry
Changes to apply the right coding style
Change the definition of Enquiry Manager service 
to remove security context from the arguments.
Added unit test of the EnquiryManager class
Added license header in each php file