[pitivi] (6 commits) Non-fast-forward update to branch wip-speed-control

[Alexandru Băluț <alexbalut src gnome org>]

The branch 'wip-speed-control' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  313e8f0... undo: Join successive similar operations on title clips
  7485df6... tests: Exercise modifying the title
  8705274... Add support for time effects
  6c6e1a0... elements: Stop showing unused track elements
  b9e9ad1... Use GES frame APIs to do frame stepping

Commits added to the branch:

  eec855a... undo: Join successive similar operations on title clips (*)
  c470f30... tests: Exercise modifying the title (*)
  d25fb36... Update Ukrainian translation (*)
  5dc2491... Update Serbian translation (*)
  57c084a... Add support for time effects
  7b963e4... Use GES frame APIs to do frame stepping

(*) This commit already existed in another branch; no separate mail sent