I18n: Update translation hr (74%).

287 translated messages, 100 untranslated messages.

Transifex (https://www.transifex.com/projects/p/xfce/).
I18n: Add new translation cs (60%).

233 translated messages, 154 untranslated messages.

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