Current version of JSON output functions perform escaping of non-ASCII characters into \uXXXX sequences, although json allows to use any Unicode character in strings. When working with non-Latin-1 based texts, this lead to additional traffic.

Given patch fixes this problem, leaving old behavior by default, but adding new option to output functions, that now accept :escape-chars option, that control how non-ASCII characters in string will output. When this option has value 'true' (default), then hex sequences are used for these characters, and when 'false', then characters are output as-is

P.S. I sent CA at start of June, so Rich should already have it