Action buttons: default to a horizontal button layout in the deskbar mode
Action buttons: fix compilation warning
I18n: Update translation nb (85%).

337 translated messages, 56 untranslated messages.

Transifex (https://www.transifex.com/projects/p/xfce/).
I18n: Update translation nb (97%).

382 translated messages, 11 untranslated messages.

Transifex (https://www.transifex.com/projects/p/xfce/).
I18n: Update translation nb (100%).

393 translated messages.

Transifex (https://www.transifex.com/projects/p/xfce/).
Tasklist, removed an optimization causing problems on some systems.

This optimization makes little difference to performance but causes
problems in some situations where more than one button become active
at once.
Tasklist, fixing race condition between desktop and window switching

In some cases clicking on a button switches to another desktop but fails
to activate the application (another, previously activated window gets
the focus).

Not sure why gtk_main_iteration works and not e.g. XSync but it fixes
the problem on affected systems.
ArrowButton: make sure the button relief is preserved during blinking
Scroll wheel cycling wrap