qa-dev's virtualhost config

There was something really fishy with qa-dev's apache2 config. It does 
not seem to be reading the DocumentRoot for *:80 (but it does for 443, 
go figure), and as a result, http://qa-dev.w3.org/ was 404.

I tried a few things without success (The logs were a bit scary, the 
server was looking at docs in /htdocs, which is written nowhere in the 
config). Ended up adding a DocumentRoot directive directly in 
apache2.conf, and it works.

If any of you has a cleaner solution, feel free to try it out.

-- 
olivier