Problems with localization files

[RobertoRDT]

Miscellaneous problems with localization files:

• with EN as default language, at first loading all languages have Italian couple "Versi/Prosa" for the button instead of appropriate translations; changing to another language, pushing the button to set "Prosa" and going back to EN fixes this;

• tooltip for "Verses/Prose" is "versi/prosa" for all languages, actually it is not in the localization files;

• tooltip for DE "Listen" is "Listen öffnen" instead of "Listen öffnen"; same for "Suchen" and all buttons where there is an opening ("öffnen") action;

• in general, all special characters in German are not rendered within the tooltips, only the entities are shown, see f.i. the "Vergrössern" button; the same doesn't happen for the Czech localization.