Merge branch 'master' of ssh://jomand@git.sv.gnu.org/srv/git/lilypond

Merge branch 'master' of ssh://jomand@git.sv.gnu.org/srv/git/lilypond

* 'master' of ssh://jomand@git.sv.gnu.org/srv/git/lilypond:
  GDP LM 3.3.4 Explaining \context
  Updates to chords.itely, fretted-strings.itely
  Compile fix.
  Update from Kurt.
  Update fretted-strings.itely
  staff-symbol-referencer.cc: Junk redundant functions.
  Robustify Staff_symbol_referencer::on_line ().
  Update fretted-strings.itely
  Change type predicate for 'layer to integer.
  Replacing "User Manual" with "Notation Ref" in SL

Conflicts:

	Documentation/user/fundamental.itely