In addition to the current tooltip, which shows color legend, if user
holds the Shift key during hovering we show another tooltip which
contains a table of contents for the piece under the moue cursor. The
table lists file sizes and names. If the cursor points to a part of a
file which spans several pieces, those pieces are highlighted.
Some browsers do not download files, intended for immediate opening,
into a temporary directory, and thus a regular download directories
accumulate those unneeded files.
The option allows qBittorrent to clean after itself and delete those
files whether they were succesfully added or not (user-selectable
policy).
