[pitivi] (9 commits) ...Merging translations

[Edward Hervey <edwardrv src gnome org>]

Summary of changes:

  ef33aa5... ui/timeline.py: removed spacing between scrollbar and timel
  64e6d9e... Remove some trailing spaces added in the last commit.
  d7b447f... mixer: track: undo: curve: Only allow alpha passthrough whe
  c1e87c9... tests: Add unit tests for alpha passthrough logic
  bed6ae9... timeline/timeline_undo: update method to reflect a change i
  dce2036... tests: mixer: track: Add tests for removing track objects w
  9f053b8... tests: Extend alpha test coverage
  b44a97c... mixer: Remove some redundant code
  f355d6d... Merging translations