Re: Fixes heights and pure heights of stems. (issue 4898044)

[bordage . bertrand]

Benchmark done on a book with many beams:
without the patch: 51.8s and 80 pages
with the patch: 52.2s and 83 pages

I also noticed some ugliness's between beams and figured bass. The
figures stay exactly where they were, but the stems are longer and
collide a bit with them.

Bertrand

http://codereview.appspot.com/4898044/