formatting of elided syllable in lyrics

[Graham King]

Where two syllables are set to the same note, is there a way to apply 
formatting to the second?  I hope I've not missed something obvious in the NR 
or the Snippets Repository.

In the following example, "eleison" is editorial and should be italicised.  The 
upper line of lyrics has the correct spacing but not the desired italics:

\version "2.19.82"

ital = \override LyricText.font-shape = #'italic
italx = \revert LyricText.font-shape

{ c'1 c' d' c' }
\addlyrics { ky -- rie_e -- lei -- son }
\addlyrics { ky -- rie_ \ital e -- lei -- son \italx }