Method writeNull

MonaCore/include/Mona/StringWriter.h:45–45

	void   writeString(const char* value, UInt32 size) { append(value,size); }
	void   writeBoolean(bool value) { append( value ? "true" : "false"); }
	void   writeNull() { packet.write("null",4); }
	UInt64 writeDate(const Date& date) { std::string buffer; append(date.toString(Date::SORTABLE_FORMAT, buffer)); return 0; }
	UInt64 writeBytes(const UInt8* data, UInt32 size) { append(data, size); return 0; }