Add simple 'function' for 'D. C. al capo/segno/fine etc'

[James]

I'd personally like a 'markup' function that simplifies 
adding 'D.C..' of 'D.S..' statements on a piece of 
music.

I usually have to end up having to use the method of making 
the string I want a rehearsal mark and 
then putting that rehearsal mark 'DOWN' and 
futzing about with font sizes, and then I still have to add a 
Segno makr of a fine etc.

As far as I can make out for standard western 
notation there are 6 types of this 'notation'.

Da Capo

Da Capo al Fine

Da Capo al Segno

Da Capo al Segno e poi la Coda

Dal Segno

Dal Segno al Fine

So you could have two functions

\dacapo

\dalsegno

with options like

\dacapo \fine \segno \coda

\dalsegno \fine

The two base commands (\dacapo and \dalsegno) can 
be added like a regular markup except instead of 
having to worry about alignment, they always occur 
right aligned at the end of the bar instead of in 
relation to the note like say {a1\fermata}.

Also perhaps if you have some kind of simple numerical addition

example:

{ bes (aes) g\> f aes (g) f e | f4-.\! r r_\markup {\dalsegno 6 \fine 16} }

This would automatically mark up the text and print 
the segno mark at bar 6 and the 'fine' text at the 
end of bar 16. You could still use the _ or ^ signs if 
you wanted above or below the stave.

Anyway, I think you get the idea.