Merge remote-tracking branch 'origin' into translation
Strip trailing whitespaces (not trailing newlines).
web-fr: updates essay, download and intro
Doc-fr: updates extending and usage
Doc-fr: updates LM

 - learning
 - common notation
 - fundamental
 - templates
 - tweaks
Doc-fr: updates to NR
Doc-fr: updates texidocs
Doc-fr: updates texidocs
Issue 4007: Fix parts of apparently dead code make-stream-event

It is not clear whether the code will be operative for its intended purpose
afterwards, but leaving it in broken state is not going to help.
Fix ly:make-stream-event to receive a symbol list rather than a symbol as event class
Import snippets from LSR and delete initial batch in snippets/new
Issue 4005: Set X-parent of TextScript to NoteColumn instead of PaperColumn

This makes TextScripts consistent with DynamicTexts and LyricTexts.
This is a follow-up to commit 59a842eba0f7ad78289a58a (Issue 2245).

Setting TextScript.cross-staff property to #f is required to ensure
that there are no collisions between TextScripts and cross-staff notes:

\context PianoStaff <<
  \new Staff = "up" {
    b8[
    \change Staff="down"
    d'] ^"text"
  }
  \new Staff = "down" {
    \clef bass
    s4
  }
>>

(see also beam-cross-staff-auto-knee.ly)

As far as I can see, we don't want TextScript.cross-staff to be true
in any situation, because it would result in unwanted collisions.

Why it worked before: cross-staff property in this example evaluated to #f,
but only because of a bug in Script_interface::calc_cross_staff.  That
function should have marked the TextScript as cross-staff if the stem
of the note to which TextScript was attached was cross-staff, but it
didn't work correctly because it expected the parent of the TextScript
to be a NoteColumn, while it actually was a PaperColumn.  When I changed
the parent to be a NoteColumn, the function started working correctly
and marked the TextScript as cross-staff, so I had to change the default
value of the property.
CG: Update of Patchy instructions

Issue 4013

Added fuller explanatory information regarding Patchy.
Doc: NR - Pitches.itely - dodecaphonic-no-repeat text alt

Issue 4023

Came out of issue 3992

Corrected wording for dodecaphonic-no-repeat
accidental style.
Issue 4019: binding-offset not properly scaled along with paper size

This will unfortunately affect all previous uses of binding-offset which
likely were employed using trial-and-error.
Issue 4021: Remove obsolete restrictions from define-*-function docstrings
Remove warning when there are no noteheads to attach lyrics to.

The warning was added to address issue 248, but it is now moot after
issue 3254 (c73b41b3e7be6d7): attaching lyrics to a note-less context
(like Devnull) is perfectly legal now.
Make list of `non-staff lines' easier to find in IR.

Linking from the NR to the Axis_group_engraver IR entry
directs the reader to the list of staff contexts and
`non-staff line' contexts.
Merge remote-tracking branch 'origin/master' into translation
Merge branch 'translation'