I18n: Update translation tr (100%).

216 translated messages.

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

216 translated messages.

Transifex (https://www.transifex.com/projects/p/xfce/).
Fix some runtime warnings

This patch fixes it so that the file icon manager won't attempt to
remove pending icons from the icon view as they won't be there yet.
It also removes an icon migration function that shouldn't be needed
anymore.
Fix keyboard cursor movement in the icon view
I18n: Update translation sl (94%).

205 translated messages, 11 untranslated messages.

Transifex (https://www.transifex.com/projects/p/xfce/).
I18n: Update translation sl (95%).

206 translated messages, 10 untranslated messages.

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

216 translated messages.

Transifex (https://www.transifex.com/projects/p/xfce/).
I18n: Update translation zh_CN (99%).

214 translated messages, 2 untranslated messages.

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