Description
As discussed at http://markmail.org/message/ehdxwhxucxslkne4 we may use Jackson instead of Gson to read/write the layout **Repr classes.
As a bonus it should be very easy to create .xml version of them and provide XML schema (.xsd) so it is easier for application developers to edit and validate in the IDE.
Optional: with tool like https://github.com/fnogatz/xsd2json we may create JSON schema as well.