ArduinoJson 5.7.0 * Templatized all functions using `String` or `std::string` * Removed `ArduinoJson::String` * Removed `JsonVariant::defaultValue<T>()` * Removed non-template `JsonObject::get()` and `JsonArray.get()` * Fixed support for `StringSumHelper` (issue #184) * Replaced `ARDUINOJSON_USE_ARDUINO_STRING` by `ARDUINOJSON_ENABLE_STD_STRING` and `ARDUINOJSON_ENABLE_ARDUINO_STRING` (issue #378) * Added example `StringExample.ino` to show where `String` can be used * Increased default nesting limit to 50 when compiled for a computer (issue #349)