Re: Issue 5621: Improve rehearsal mark position at beginning of staff (issue 547340043 by address@hidden)

[nine . fierce . ballads]

This is ready for a full review now.

I don't think any new test cases are required.

I haven't looked very deeply into the potential use of an unpure-pure
container.  It looks like unpure-pure containers are used for vertical
placement, and this is horizontal.  If that answer is not satisfactory,
let me know and I'll spend more time learning about it, but I'd rather
work on other things.



https://codereview.appspot.com/547340043/