Sadegh

Provide a generic json mapper for any entity.

1

Hi Fernando, I changed `UserEntityJsonMapper` to a generic class named `EntiityJsonMapper`, so I can deserialize any kind of entity. Hope you like it!

Non-static inner classes are not good practice in general, and whenever the inner class really doesn't need access to its enclosing class object (in this case `ContactsAdapter`), we should make...