Issue 3777: Code improvements in satb.ly

Issue 3777: Code improvements in satb.ly

  Comment out \version to ensure user still sees
  a warning if he omits one

  Add prefix to macro and function names to avoid
  potential clashes with user names

  Return *unspecified* if macros are called with
  an undefined argument rather than #{#}

  Remove unnecessary use of "identity"

  Use "and" rather than "if" when false condition
  would return #f

  Convert tabs to spaces
    
  Use $ rather than # in \layout

[Trevor Daniels, 2014-01-08 11:53:22]

Comment out \version

[Trevor Daniels, 2014-01-08 14:32:49]

Return \layout to original state

[Trevor Daniels, 2014-01-09 14:27:04]

Setting Layout now works

[Trevor Daniels, 2014-01-14 00:11:11]

This patch has been superseded by an improved version
provided by Devon Schudy (see Issue 3799) and so is
being withdrawn and closed.

[Trevor Daniels, 2015-03-07 23:34:48]

Rebase on current master

[Trevor Daniels, 2015-03-12 15:33:38]

Pushed to staging as
7225065e1958c770f4e450ebc6f32366afd78a83

Author: Trevor Daniels <t.daniels@treda.co.uk>  2015-03-07 22:45:00
Committer: Trevor Daniels <t.daniels@treda.co.uk>  2015-03-12 15:26:48

    Issue 3777: Code improvements in satb.ly
    
      Comment out the \version statement to ensure
      users still are warned if they omit their own
      \version statement
    
      Add prefix to macro and function names to avoid
      potential clashes with user names
    
      Return *unspecified* if macros are called with
      an undefined argument rather than #{#}
    
      Remove unnecessary use of "identity"
    
      Use "and" rather than "if" when false condition
      would return #f
    
      Convert tabs to spaces
    
      Use $ rather than # in \layout

Closing ...