Refactor GenericReader::ParseString(). Extract logic independent of kParseInsituFlag to GenericReader::ParseStringToStream(). Eliminated RAPIDJSON_PUT() macro and made the function more readable.
Refactor GenericReader::ParseString(). Extract logic independent of kParseInsituFlag to GenericReader::ParseStringToStream(). Eliminated RAPIDJSON_PUT() macro and made the function more readable.

doo/rapidjson,doo/rapidjson,doo/rapidjson