And correct a few comments (translation and grammar)

Change-Id: Ifafa521c683e9ca65aeba8031cd4cbfc1fadc137
Reviewed-on: https://gerrit.libreoffice.org/54888Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>
Reviewed-by: Armin Le Grand <Armin.Le.Grand@cib.de>