Issue 2024: Let #{ ... #} pass its $ handling to environment cloning (issue 5341049)

[tdanielsmusic]

I don't claim to understand much of this, but the resulting
simplification seems worth the pain to me.  The expectation that
convert-ly will generate many changes to (advanced) user code suggests
changes.tely needs a clear notice adding explaining what has been done.

Trevor


http://codereview.appspot.com/5341049/diff/2001/Documentation/extending/programming-interface.itely
File Documentation/extending/programming-interface.itely (right):

http://codereview.appspot.com/5341049/diff/2001/Documentation/extending/programming-interface.itely#newcode44
Documentation/extending/programming-interface.itely:44: It extracts the
Lilypond code block and generates a call to the
LilyPond

http://codereview.appspot.com/5341049/diff/2001/Documentation/extending/programming-interface.itely#newcode47
Documentation/extending/programming-interface.itely:47: the lexical
environment of the Lilypond code block, so you have access
LilyPond

http://codereview.appspot.com/5341049/diff/2001/Documentation/extending/programming-interface.itely#newcode48
Documentation/extending/programming-interface.itely:48: to local
variables and function parameters at the point the Lilypond
LilyPond

http://codereview.appspot.com/5341049/