Code review comment for lp:~paul-lucas/zorba/bug-1025622

http://json.org/ says that not only '"' and '\' need to be escaped with a backslash but also a solidus '/'.

And, some control characters have special backspace escapes: backspace (x8 -> \b), formfeed (xC -> \f), newline (xA -> \n), carriage return (xD -> \r) and HTab (x9 -> \t). Currently, they are serialized as hex.

I would propose to add tests for those as well.