Fingering should be above the beam automatically

[Raphael Manfredi]

Here's a file that demonstrates the problem.  I'd appreciate if that
could be added to the "regression tests".

------------------------------------------------------------------------
% Fingering should be ABOVE the beam automatically.
% In this example, we see overlapping with fingering on the second
% and third chords.
\version "2.6.3"
\new Staff {
        \clef treble \time 3/8 \key a \minor
        \relative c'' {
                 a8 r16 <e-1 c'-5> <f-2 c'-5> <e-1 g-3 c-5> |
        }
}
------------------------------------------------------------------------

Raphael