Use @dots{} instead of ... in manuals (issue 10296043)

[lilyfan]

Reviewers: dak, Trevor Daniels, Graham Percival,

Message:
Follow up of issue 3392


Description:
Use @dots{} instead of ... in manuals

 Web: intro and helpus
 Doc: usage, extenting and learning

Please review this at https://codereview.appspot.com/10296043/

Affected files:
  M Documentation/extending/programming-interface.itely
  M Documentation/extending/scheme-tutorial.itely
  M Documentation/included/compile.itexi
  M Documentation/included/helpus.itexi
  M Documentation/learning/common-notation.itely
  M Documentation/learning/tweaks.itely
  M Documentation/usage/lilypond-book.itely
  M Documentation/usage/running.itely
  M Documentation/usage/suggestions.itely
  M Documentation/usage/updating.itely
  M Documentation/web/introduction.itexi