Added missing translations.
Reviewed and fixed strings marked fuzzy.
Changed date-format to something resembling the usual Dutch notation.
Changed names of months to lowercase.
Changed translation of divemaster from diveinstructor to diveleader.
Fixed some typos.
Signed-off-by: Reinout Hoornweg <reinout@xs4all.nl>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>