wml build logs: one with errors only ?

[Simon Paillard <simon.paillard@resel.enst-bretagne.fr>]

Hello,

On http://www-master.debian.org/build-logs/webwml/ that would help much
to have one version of the log file only with stderr, in order to
identify them easily.

Everyone could do "grep -B1 Stop wml_run.log" after downloading the
file, but it needs efforts :p

-- 
Simon Paillard