[branch] 1.x R4946 (latest) XML export of page breaks

If a score only has line breaks encoded at the end of staves, and I XML export and re-import within MS 1.x, the final line break on each page is converted to a page break, contrary to what I have explicitly set. It should stay at what I have set it to.

Also, any line or page break symbol set in the final measure of the score is not exported (or imported).