abc2ly - church modes, tempo, "-b" option

[Hans Aberg]

Some bugs in abc2ly (LilyPond) 2.11.34, probably easy to fix:

* When using a church mode like E Dorian, ABC expects the pitches to  
be interpreted relative to the key signature of this mode, that is  
the two sharps F# and C# in this case; abc2ly just interprets this  
mode as E major, with four sharps F#, C#, G#, D# then. In other  
words, in ABC E Dorian, the written notes C (resp. F) should be  
mapped onto C# (resp. F#), and the others should be as written. But  
abc2ly also maps G (resp. D) onto G# (resp. D#), and further writes  
the key signature E major instead of E Dorian. (Example below.)

* abc2ly does not write the tempo mark. An ABC source file may have  
this entry:
  Q:1/4=120
which should be translated to
  \tempo 4 = 120

(I think it would be nice to fix this, because the MIDI output of  
LilyPond seems more accurate than of other ABC conversion engines, so  
it might lead to more use of LilyPond.)

* Then "-b" option seems broken; the equivalent "--beams=None" works,  
though.

* When executing "abc2ly -h": a typo in the word "success".

  Hans Aberg


Example: The ABC input
T:abc2ly bugs
M:C
L:1/8
Q:1/4=120
K:E Dorian
E<BB>A B>AB<d|F<DA>D B>DA>F|e>ce<g e>Be<g|

I think should have the typeset output of the LilyPond source below,  
where I have tried to do minimal editing on the output of abc2ly. (It  
seems also writing the wrong \version in the output.)
----
\version "2.7.40"
\header {
        footnotes = ""
        tagline = "Lily was here 2.11.34 -- automatically converted from ABC"
        title = "abc2ly bugs"
}
voicedefault =  {
\set Score.defaultBarType = "empty"

     \override Staff.TimeSignature #'style = #'C
 \time 4/4 \key e \dorian
 \tempo 4=120
  e'16[    b'8.    b'8.    a'16]    b'8.[    a'16    b'16
   d''8.]  \bar "|"   fis'16[    d'8.    a'8.    d'16]    b'8.[    d'16
a'8.    fis'16]  \bar "|"   e''8.[    cis''16    e''16    g''8.]     
e''8.[
b'16    e''16    g''8.]  \bar "|"
}

\score{
    <<

        \context Staff="default"
        {
            \voicedefault
        }

    >>
        \layout {
        }
        \midi {
                \context {
                 \Score tempoWholesPerMinute = #(ly:make-moment  120   4 )
                 }
}
}
----