Default strings can now be translated

This adds the ability to translate the strings used in the default dialogs, by simply updating the `defaultStrings` in the module:

    angular.module( "dialogs" ).value( "defaultStrings", {
      close : "Schließen",
      pleaseWait : "Bitte warten",
      percentComplete : "% fertig",
      ok : "OK",
      yes : "Ja",
      no : "Nein"
    } );

Any other solution would be just as fine for us :)