Injecting moment in SVG output

[Mathieu Demange]

Hello all,

I need a way to inject an event's moment (like what event-listener.ly 
produces) into its corresponding grob id property (so it'll appear in 
the SVG output).

I tried all kind of things but nothing works. I'd share all my attempts 
if needed but if someone thinks of something which would work, I'd be 
delighted.

Thanks in advance.

Cheers,

Mathieu