TotalStorage and RemainingStorage are not documented in RHP4

[mike76-dev]

The fact that both TotalStorage and RemainingStorage are expressed in sectors and not in bytes as before is not documented. It can only be inferred from the API docs (even there one has to look at the code to understand that), or obtained through a trial-and-error exercise.

Whoever commented the old siad code, they certainly did a great job. I wish the same were true for the new code, too.