Cross-voice arpeggios do not respect arpeggio types

[Ole V . Villumsen]

> I'm not top posting.

The arpeggio types described in NR 1.3.3 including bracketed arpeggios
cannot be produced accross staves. When I specify \set
PianoStaff.connectArpeggios = ##t with either of \arpeggioArrowUp,
\arpeggioArrowDown, \arpeggioBracket, \arpeggioParenthesis and
\arpeggioParenthesisDashed, a normal arpeggio line is always printed, i.e.,
the type specified is ignored.

Tiny example:

\version "2.18.0"

\new PianoStaff \relative c'' <<
  \set PianoStaff.connectArpeggios = ##t
  \new Staff {
    \arpeggioArrowUp
    <e, c>4\arpeggio
    \arpeggioArrowDown
    <e c>4\arpeggio
    \arpeggioBracket
    <e c>4\arpeggio
    \arpeggioParenthesis
    <e c>4\arpeggio
    \arpeggioParenthesisDashed
    <e c>4\arpeggio
  }
  \new Staff {
    \clef bass
    \arpeggioArrowUp
    <g, c,>4\arpeggio
    \arpeggioArrowDown
    <g c,>4\arpeggio
    \arpeggioBracket
    <g c,>4\arpeggio
    \arpeggioParenthesis
    <g c,>4\arpeggio
    \arpeggioParenthesisDashed
    <g c,>4\arpeggio
  }
>>

The same problem is with arpeggios connected across voices in the same
staff. Tiny example:

% expected: bracket spanning both note heads
% actual output: normal arpeggio line spanning both note heads

\version "2.18.0"

\new Staff = rh \with { \consists "Span_arpeggio_engraver" } {
  \set Staff.connectArpeggios = ##t
  \arpeggioBracket
  << { g'\arpeggio } \\ { c'\arpeggio } >>
}

PS I tried to post this last week, but I think it got lost somewhere. Please
excuse if it gets doubled by mistake.