Docs for 3.0

[Graham Percival]

There's two things I need help with, somewhat urgently before 3.0:

1)  In the manual, "Controlling formatting of prefatory matter" 
(currently 5.3.10): there's an example of doing weird stuff with the 
clef and key signature, and no explanatory text.  If it's just an 
example of doing weird stuff, I can write some text.  Although I'm not 
certain how much it adds to the manual... would anybody mind if we just 
delete this section?  (perhaps sticking the example into the "tricks n' 
tips" section?)

2)  Piano templates.  I propose deleting "piano-4-voices.ly".  I'm not 
sure whether to move "piano-lyrics.ly" (lyrics centered between the 
staffs) into the manual, or not bother saving that one.  Opinions?
The real problem is "piano-dynamics.ly" (dynamics centered between the 
two piano staffs).  It sounds like a good template to have, but I don't 
understand the template myself, and there's a bunch of ugly stuff in 
there (like extra-offset).  Could a piano player have a look at this 
and simplify it?  Or make a completely new template that does the same 
thing?

Cheers,
- Graham