Make "Adding extra fingering with scheme" snippet do something useful

Make "Adding extra fingering with scheme" snippet do something useful

This snippet was never operative in 2.16 due to the EventChord changes
of issue 2240.  This updates it into using a few 2.16 features in
order to make things simpler while retaining the basic purpose.


Also:

Run scripts/auxiliar/makelsr.py

[thomasmorley651, 2013-09-27 23:53:50]

LGTM

Question: 
considering LSR-update, I recently added an earlier version of it to the LSR
http://lsr.dsi.unimi.it/LSR/Item?id=887
Should I replace it with this one?

[dak, 2013-10-01 05:55:11]

On 2013/09/27 23:53:50, thomasmorley651 wrote:
> LGTM
> 
> Question: 
> considering LSR-update, I recently added an earlier version of it to the LSR
> http://lsr.dsi.unimi.it/LSR/Item?id=887
> Should I replace it with this one?

I think that depends on whether it will compile with the current LSR version. 
This version will work either before or after issue 2240 (one motivation for the
change) but it might require code not available in 2.14.