[tlbuild] bengalli ebond.py uses deprecated sre module

[Karl Berry]

    Does anybody run TL scripts under python 1.x?  

Dunno, but doubt it.  

   and I don't have any idea what ebong is supposed to do.

Me either.  Therefore I do not plan to make any changes.

If you can't find the authors and feel strongly enough to make whatever
changes need to be made to use re, perhaps CTAN would accept a new
version of ebong.py.