I18n: Update translation hu (100%).

739 translated messages.

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

739 translated messages.

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

739 translated messages.

Transifex (https://www.transifex.com/projects/p/xfce/).