Ticket #2101: allow skip directory scanning before file operations.

  * (compute_dir_size_create_ui): add "Skip" button to the "Directory
  scanning" progress dialog.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Handle "Skip" button in directory scanning status dialog.

Don't show total size, number and time values of file operations
if directory scanning was skipped before.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Refactoring of directory size calculation.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
While scanning directories, print directory counter and size

...in addition to directory name.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Update all po/*.po files.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Merge branch '2101_skip_directory_scanning'

* 2101_skip_directory_scanning:
  Update all po/*.po files.
  While scanning directories, print directory counter and size
  Refactoring of directory size calculation.
  Handle "Skip" button in directory scanning status dialog.
  Ticket #2101: allow skip directory scanning before file operations.