[lilypond/f17] (10 commits) ...Merge branch 'master' into f17

[Jon Ciesla]

Summary of changes:

  ccad66b... 2.15.30. (*)
  7fc67be... 2.15.31. (*)
  559d8be... 2.15.32. (*)
  df95047... 2.15.33. (*)
  25f5501... 2.15.34. (*)
  df99bb5... 2.15.35. (*)
  6af331c... 2.15.36. (*)
  93ef746... 2.15.37. Spec cleanup. (*)
  51cbaab... 2.15.38. (*)
  cf31890... Merge branch 'master' into f17

(*) This commit already existed in another branch; no separate mail sent