(critical) boundary boxes remove important info in docs

[Graham Percival]

Problem still exists in 2.7.39

Some score examples have important notation that gets cut off (due to 
margins, .eps boundary boxes, or whatever).  The worst doc sections are

8.2.5 Instrument names
  (instrument names get cut off in the middle of a letter)
8.5.1 Balloon help
  (we can't see the balloon at all)
10.4.2  Page formatting
  (no system separator is visible)

I believe that 8.5.1 was broken in the 2.6 manual, but 8.2.5 and 10.4.2 
are definitely regressions.
- Graham