RingCounter length++

[joulupunikki]

The length of RingCounter objects is requested length++ since the counter starts at zero. This is likely the cause of hex_buffer contents appearing off by one for each column and the confusion when reverse-engineering planet maps. DOH! 👊 👎 😡 If so then this is a bug in Phoenix, not in EFS hex_buffer, and it took almost three years to notice ... ever so slight, subtle and fundamental flawww. Well, at least fixing #30 should be easier now ...