Bytes attaches a unit to the bytes value and makes it human readable.

Filename takes the given filename and rotates it like a carousel through a fixed length string of maxLen.

Progress builds a string of length `width` that indicates the `percent` progress being made by filled # characters.

Speed formats the given bytes per second value to a human readable format.

TransferStatus takes the terminal width `twidth` and builds a string occupying the whole width indicating the current transfer status.