Unable to italicize lyrics in 2.18, 2.19

[Paul Schmitz]

> I'm not top posting.

Hi,

For many years I have used the documented instructions to italicize lyrics,
e.g. 

\score {
<<
\new Lyrics \with {
\override LyricText.font-shape = #'italic
\override LyricText.self-alignment-X = #LEFT
}
{ \dialogue }
\new Staff {
\new Voice { \music }
}
>>

(example from 2.18 notation reference)

However, font-shape is no longer listed as an interface for LyricText and
this instruction appears to be ignored.  If it's been removed intentionally,
is there a replacement or workaround?

Thanks,
Paul