Forcing Piano Staff spacing in 2.11

[Benedict Singer]

Hi all,

I recently moved some of my piano and piano + instrument pieces to  
version 2.11, and the new spacing code is in some instances placing  
the two staffs of the piano staff closer than I'd like, often if there  
are no dynamics. I'm fine with it widening the spacing if it needs to,  
but is there a way to enforce a minimum spacing of the two staffs? In  
2.10 I would tweak the forced-distance value to control the spacing on  
all the piano staffs, but that option seems to have disappeared in  
2.11; the compiler complains about it, and the equivalent section in  
the 2.11 docs doesn't mention it. Thanks!

Ben