How to set a constant vertical distance?

[prut1105]

Hello,

One thing that is bothering about the output I create with
Lilypond is that the staves have a variable interval. (See
attachment sample file.) This is caused by the presence/absence
of dynamics.

In a piece from Mutopia Project I noticed the sheet music in
the PDF file has the layout I like.
  http://www.mutopiaproject.org/cgibin/piece-info.cgi?id=651

When checking the .ly file it seems the following command
  \override VerticalAlignment #'forced-distance = #4.5
is used to achieve this. In v2.12.3, however, this property
has been removed (from searching the internet this apparently
happened in v2.11).

I find this varying height uncomfortable and prefer this
separation to be the same for all lines. How can I
force/tweak Lilypond to do this?

Many thanks in advance,
   Herre

Test.ly
Description: Text document