3.15.2
======
* Fix visual glitch of window preview outline in overview [Chris; #699044]
* Change user facing name of "Captive Portal" to "Network Login" [Elad; #737198]
* Port to Python 3 [Slavek; #732478]
* Hide Airplane mode indicator when g-s-d says so [Cosimo; #736292]
* Allow translators to change non-work days [Lavi; #664645]
* Delay invocation of caribou daemon until really needed [Daiki; #739712]
* Don't lock screen after crash if locking is disabled [Adel; #704884]
* Improve layout of extension installation dialog [William; #739888]
* Fix workspace changes from app picker [Yuki; #737534]
* Preload all ibus input sources in user configuration [Takao; #695428]
* Properly remove network connections from list [Ryan; #740227]
* Support CSS margin property [Carlos; #728437]
* Improve handling of BUSY application state [Phillip; #736492]
* Fix erroneous week numbers in calendar [Florian; #736722]
* Misc. bugfixes and cleanups [Darcy, Yuki, Alexander, Eskild, Bastien, Cosimo, Colin,
  Ray; #738725, #739497, #739241, #672500, #739822, #740074, #704163, #740141]

Contributors:
  Yuki, Lavi .A, Elad Alfassa, Cosimo Cecchi, Takao Fujiwara, Adel Gadllah,
  Eskild Hustvedt, Chris Johns, William Jon McCann, Slavek Kabrda, Ryan Lortie,
  Florian Müllner, Bastien Nocera, Christian Persch, Carlos Soriano,
  Jasper St. Pierre, Ray Strode, Alexander Tsoy, Daiki Ueno, Colin Walters,
  Phillip Wood

Translations:
  Jorge Perez Perez [an], Daniel Martinez [an], Daniel Mustieles [es],
  Trần Ngọc Quân [vi], Changwoo Ryu [ko], Kjartan Maraas [nb],
  Yosef Or Boczko [he], Marek Černocký [cs]