Convert the passed in JSON string into a Java object graph
that consists solely of Java Maps where the keys are the
fields and the values are primitives or other Maps (in the
case of objects).
Write out special characters "\b, \f, \t, \n, \r", as such, backslash as \\
quote as \" and values less than an ASCII space (20hex) as "\\u00xx" format,
characters in the range of ASCII space to a '~' as ASCII, and anything higher in UTF-8.