Syntax to unset avoid-slur by default

[Maximilian Albert]

Hi,

in answer to Graham's request a couple of days ago I agreed to add the
avoid-slur settings to scm/script.scm. When it came to Gregorian chant, I
thought it might be best to leave the value unset by default for those scripts
(since slurs don't make sense in chant anyway, do they?). My moderate knowledge
of scheme seems to imply that

  (avoid-slur . nil)

the right way to do that. Is this correct?

Thanks,
Max