3.15.4
======
* Add mode parameter to AcceleratorActivated signal [Florian; #711682]
* Fix PID based window/app association [Sebastian; #736527]
* Fix current day highlight on day change [Sebastian; #742492]
* Switch to vp9 for screencast recordings [Adel; #742744]
* Disable IBus input sources on password entries [Takao; #730628]
* Make slider scrolling smoother [Adel; #742648]
* Allow move-up shortcut to move window above top workspace [Florian; #665764]
* Misc. bug fixes [Adel, Rui; #742748, #742824, #741114]

Contributors:
  Cosimo Cecchi, Takao Fujiwara, Adel Gadllah, Sebastian Keller, Rui Matos,
  Florian Müllner, Jasper St. Pierre

Translations:
  Andika Triwidada [id], Matej Urbančič [sl], Saibal Ray [bn_IN],
  Inaki Larranaga Murgoitio [eu], Stas Solovey [ru], Kjartan Maraas [nb],
  Balázs Úr [hu], Marek Černocký [cs], Rafael Ferreira [pt_BR],
  Bernd Homuth [de], Daniel Mustieles [es], Fabio Tomat [fur]