combine voices dot/nodot

[Jan-Peter Voigt]

Hello List,

on p. 307 of Elaine Gold's book ("behind bars") she writes, it is an 
accepted keyboard convention that notes of unequal duration may share a 
notehead to save space.
This is here example:
--snip--
<<
  \relative c'' {
    c8. d16 e c d g
  } \\ \relative c'' {
    c16 g e d' e8. g16
  }
>>
--snip--
How can I let lilypond share noteheads?

I know I can
\once \override NoteColumn #'force-hshift = #-.5
but then I have to estamite the shift value by trial and error (I assume 
it will be +/-0.5 in most cases, but not in all).

Is there an override, to allow this "collision"?

Cheers,
Jan-Peter