1.3.1* Collision resolution

[Mark Hindley]

I have found a case where the automatic collision resolution fails. In
the following fragment, the first chord the crotchet overrides part of
the minim chord, but the second one resolves the collision correctly.

It is certainly a notation found a lot in keyboard music, so would be
worth supporting

Best

Mark

\score{
\context Staff \notes <
    \context Voice=one{\stemUp <c'2 g'> <c'2 g'> }
    \context Voice=two{\stemDown f'4 e' b c'}     
>
}