\tempo collision with cross staff beam

[Urs Liska]

Hi bug squad,

I ran into a collision bug.

With a cross-staff beam present \tempo doesn't take any objects above 
the staff into account.
If you comment out the beam in the following example the \tempo is 
correctly shifted upwards to accomodate the dynamic. Result is identical 
with 2.18.2 and 2.19.22.

This may be related to 3778, but strangely so:

- With cross-staff beam:
  Wrong output in PDF and SVG
- With beam commented out:
  PDF: correct spacing
  SVG: Same error as with beam

Urs

\version "2.18.2"

music = {
  \tempo 8 = 72
  % Also "works" with articulations that are placed above the staff by 
default
  d''8 ^\p
  % Comment out beam to see correct engraving
  [
  \change Staff = "2"
  d''
  ]
}

\score {
  \new StaffGroup <<
    \new Staff = "1" \music
    \new Staff = "2" { s4 }
  >>
}