missing crescendo spanner type

[Han-Wen Nienhuys]

address@hidden writes:
> 
> Please add an empty crescendo spanner type.  It makes sense to always
> properly mark up start and end of a crescendo with \cresc and
> \endcresc, but I would like to have e.g.
> 
> 
>    p  cresc.                              f
> 
> instead of
> 
>    p  cresc. -  -  -  -  -  -  -  -  -  - f

I've added the option to set dash-period < 0.


-- 

 Han-Wen Nienhuys   |   address@hidden   |   http://www.xs4all.nl/~hanwen