Add blank line before box line

[mcantino1]

Boxes should be preceded by a blank line, unless:
"Do not leave a blank line between boxed material and any accompanying heading, caption, directions, or source citation."

[rbeezer]

Liblouis allows for a style to specify the number of blank lines before or after an object. After works great.

Before seems to insert the lines after the top box line. Which is no good.

Perhaps I'll ask on their mailing list?

[rbeezer]

liblouisutdml is unable to fix. See liblouis/liblouisutdml#90

So #1861 should now have it under control and can close this.