Cross-staff 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.

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
  }
>>