Log Message:
qdirstat: update to 1.7

This is a stable release. It brings a number new features and some bug fixes:
* Closing the gap between sizes reported by QDirstat and sizes reported by the
  du command: Now also taking the allocated size into account.
* Now also displaying the allocated size where it makes sense.
* New "Mounted Filesystems" window showing output similar to the df command
  (but without the cruft).
* New directory selection dialog showing all (real) filesystems.
* New checkbox to cross filesystems (temporarily) in the directory selection
  dialog.
* Workaround for NTFS oddities: Ignoring hard links on NTFS.
* Added config option to ignore hard links in general.
* Added a document about Btrfs free size and how different tools tend to show
  different values: Btrfs-Free-Size.md
* Bug fixes