[LSR] Forcing fixed distance between staves

[Sebastiano Vigna]

The above snippet does not generate output (no .eps file is created).  
This was causing a number of problems. LSR now will keep people from  
inserting snippets that do not produce output. If there are cases in  
which this is not desirable, let me know. The snippet about is now non- 
approved and sports a last line (to be removed after fixing) that  
generates some output. It should be fixed so that it produces some  
output.

Ciao,

                                seba