SRTP: add LocalizedString structure
SRTP: change first classes to use localized strings
SRTP: change more classes to use localized strings
SRTP: change even more classes to use localized strings
SRTP: change even some more classes to use localized strings
SRTP: change even a few more classes to use localized strings
SRTP: new experimental version of formID_finder
SRTP: allow zero as index for empty string in LocalizedString
SRTP: update of programmes to work with LocalizedString