Added French Translations and...

Added French Translations and also removed a repeated line in the 3
previous translation files.

bladetester_calendar.label.event.delete: Delete
bladetester_calendar.label.category.delete: Delete
are now just
bladetester_calendar.label.delete: Delete

The way I did this commit was a little... erm funky, so It thinks I've
delete all those files even though I didn't/haven't. Think I've got it
all set up correctly now so shouldn't happen again.