Doc-fr: updates LM and EM

 programming-interface
 generating-output
Doc-it: proofread chapters 1.3, 1.4, 1.5 of Notation Reference
Release: bump VERSION_DEVEL.
PO: update template.
Release: update news.
Doc-it: proofread chapter 1.2 of Notation Reference
Issue 3530: Since Bison is optional, need to distribute Documentation/out/ly-grammar.txt
Issue 1523: Parenthesizing breath marks

Parenthesizing breath marks didn't work as expected.  The parentheses
were next to the breath mark, not around it.

It would appear that just giving ParenthesesItem a non-empty (but
zero) extent is enough to let it be placed correctly.
Merge remote branch 'origin/release/unstable' into HEAD
Release: bump VERSION.
Issue 3531: replaced function argument 'string' by 'const string&' where it makes sense to avoid unnecessary copying of 'string' objects.

Measurements on x86_64 (i7-2760QM, 2.40GHz) Fedora 19 with g++ 4.8.1, with
configure --enable-optimising --disable-debugging; tests run 10 times, average
elapsed time compared (/usr/bin/time)

* Bach, Concerto in E major or violin and strings, BWV 1042 (Mutopia source),
  38 pages:
  $ lilypond score.ly -> master: 15.4s, with patch: -0.1%
* lilypond regression tests (1153 .ly files):
  $ lilypond *.ly -> master: 276.6s, with patch: -2.5%
Avoid undefined behavior after "not a context mod" error in context defs
Correct errors in NR (mensural flags, \harmonic)
Correct doc examples using hspace (Issue 3544)
Doc: update outside-staff-padding; issue 2910
Detect missing fonts in ./configure.

Make sure that ./configure fails on missing fonts, either
because fc-list is missing or it cannot find them.

Also use :lang=ru to rule out fonts that miss the Cyrillic
characters.

Fixes issue 3526: ./configure should fail on missing fonts.
http://code.google.com/p/lilypond/issues/detail?id=3526
Keep bison-generated files in sync.

Use a single rule to build header and source files from
the syntax file, thus avoiding any possibility to have
`make' rebuild one but not the other, which might happen
if the syntax and target files have almost the same but
slightly differing timestamps.

See http://www.mail-archive.com/bug-lilypond@gnu.org/msg37081.html

Fixes issue 3528: Keep bison-generated files in sync.
http://code.google.com/p/lilypond/issues/detail?id=3528
Issue 3537: AU: Correct the description for convert-ly -d
Issue 3536: In cary-layout.ily, mimic autoBeaming setting in \context into \midi

For the rationale, see the output definition information in issue 3535.
Issue 3535: NR: explain context definitions within \layout and \midi

The notation manual was not really helpful regarding output
definitions and their relation to context instantiation.