error while string has Chinese punctuation

[hjf2005]

jsoncpp/src/lib_json/json_writer.cpp

Line 173 in 2f227cb

static unsigned int utf8ToCodepoint(const char*& s, const char* e) {

，。these punctuation‘s unicode is\uFF0C or ……

[cdunn2001]

Discussed in #687. But we do not know the best solution yet.