[MRTCAL\]INDEX CONVERT [/FILE IndexFile]
Check if the index file version is the latest possible. If not, the as-
sociated file on disk is automatically converted. The original file is
backup'ed to another name.
While index file version has very seldom evolutions, when this happens
it is necessary to convert 'old' files opened in UPDATE mode beforehand,
as MRTCAL writes only in latest version files.