Make sure measure/@n gets actually written

[th-we]

Because of ManuScript type coercion, @label was only written when ExternalBarNumber was the string '1'. Some fun facts about ManuScript:

• not not '1' => false (character '1')
• not not ('1' & '') => true (string '1')
• not not ('t') => true (character 't')
• not not ('t' & '') => false (string 't')

Also, ExternalBarNumberString is always set, not only if we have explicitly set deviating bar numbers.

Alternative would be to always write @label, independent of whether it differs from @n.

[ahankinson]

Ready to merge?

[th-we]

Yes, ready. As you both approved, I'll merge myself.

[ahankinson]

No worries -- I was just about to do it anyway!