Log Message:
gdl: update to 3.28.0.

Based on mef's wip/gdl.

Changes in 3.28.0

* bgo#791913 - Convert Latin-1-encoded characters to UTF-8 (Ting-Wei Lan)

* Translation: da (Ask Hjorth Larsen)

Changes in 3.26.0

None

Changes in 3.25.91

* Remove ome run time warnings (Sébastien Granjoux)
* Convert various source files to UTF-8 (Emmanuele Bassi)
* dock-object: fix gtk-doc comment for dock signal (Ting-Wei Lan)

* Translation: eo Kristjan Schmidt
* Translation: fur Fabio Tomat
* Translation: da Alan Mortensen

Changes in 3.22.0

* Really enforce GDL_DOCK_ITEM_BEH_CANT_CLOSE (Lukas K)

* Translation: oc Cédric Valmary
* Translation: fr Alexandre Franke
* Translation: pl Piotr Drąg

Changes in 3.20.0

* No changes

Changes in 3.18.0

* Use "resize" property and fix a bug in panel widget (Vladimir Motilenko)
* bgo #751239: fix preview window color (Lukas K)
* bgo #729325 - Set type hint of dragged-out windows to TOOLBAR (Lukas K)

* Translation: ca Jordi Ma
* Translation: pl Piotr Drąg
* Translation: pt Pedro Albuquerque

Changes in 3.16.0

* Translation: bs Samir Ribic
* Translation: sv Anders Jonsson
* Translation: tr Necdet Yücel, Muhammet Kara
* Translation: eu Inaki Larranaga Murgoitio

Changes in 3.14.0

* No changes

Changes in 3.13.92

* Translation: nb (Kjartan Maraas)

Changes in 3.12.0

* No change

Changes in 3.11.92

* Fix build using C++11 (Ryan Lortie)
* Fix valgrind warnings (Sébastien Granjoux)
* Update FSF's address (Daniel Mustieles)

* Translation: zh (Wylmer Wang)
* Translation: de (Christian Kirbach)
* Translation: sr (Мирослав Николић)
* Translation: lv (Rūdolfs Mazurs)