Clef change in the beginning of piece

[Pavel Roskin]

Hello!

Changing clef in the beginning of piece causes the staff clef to
change.  I tried several ways to draw the clef on the staff before
the first note.

I settled on appending the clef symbol to the time signature using
ly:stencil-combine-at-edge.  I posted my implementation to the LSR:
http://lsr.dsi.unimi.it/LSR/Item?u=1&id=792

Finally an implementation with no grace notes, no \partial, no changes
to MIDI and no changes to other voices!

I'll appreciate if somebody could please look at the snippet and tell
me if something could be improved.

-- 
Regards,
Pavel Roskin