[hack] Added \u2028 \u2029 replacement for all JSON.stringify operations

\u2028 and \u2029 are allowed inside string in JSON. But JavaScript defines them
as newline separators. Because no literal newlines are allowed in a string this
causes a ParseError. We work around this issue by replacing these characters
with a properly escaped version for those chars. This can cause errors with
JSONP requests or if the string is just evaluated.