Automatic Lyric Extenders

[Br. Samuel Springuel]

Is there a way to get lyric extenders to appear automatically when 
lyrics have been applied to a voice using `\lyricsto`?  I know how to 
manually get them to appear (with `__`), but I'm wondering if there is a 
simple setting that can be changed in an included style file that would 
allow me to make the change universally for all file in a particular 
project.

A testable snippet (not totally minimal, but it has several occasions 
where the lyric extenders could show up):

#(ly:set-option 'relative-includes #t)
\version "2.19.53"
\language "english"

% the included style file would go here

global = { \key e \major }

music = {
    e'( f-sharp') g-sharp'( a') b'-- b' c-sharp' b'( a') g-sharp'-- 
\bar "|"
    b'( a') g-sharp'--( a' g-sharp') f-sharp'( e') c-sharp'-- e'-- \bar 
"||"
}

words = \lyricmode {
    Let us love one a -- no -- ther,
    for love is of God.
}

\new Staff
<<
    \new Voice = "mel" { \global \music }
    \new Lyrics \lyricsto "mel" { \words }
>>

--
✝✝✝✝✝✝✝✝✝✝✝✝✝✝✝✝✝✝✝✝✝✝✝✝✝
Br. Samuel, OSB
St. Anselm’s Abbey
Washington, DC
(R. Padraic Springuel)

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