[tlbuild] rebuilding for TL'09

[Karl Berry]

    I rebuilt last night, but I noticed that libpng was just updated a 
    couple hours ago.  Is this important enough that I should rebuild again? 

I guess we should, yes.  Thanks for noticing.

Martin and everyone, please consider the *compilable* TL sources frozen
as of now.  If you feel something should be changed for the TL09 DVD,
I'll probably agree with you, but please check with me before
committing.  Thanks.

generalissimo-karl

P.S. Still awaiting the asymptote release ...