[PATCHS] fix waf test --testenv --screen, improve test speed

[Matthieu Patou]

> Have you tested it on a FreeBSD system?  That's all I'm waiting on, and
> asked you to do on Friday.  Otherwise, if you don't have easy access to
> one, I'll review it when I get it tested on my VM.
No I don't have access to FreeBSD system easily, I'm pretty confident 
that waf test --screen --testenv will not be more broken than today on 
Freebsd.
If someone else with Would be nice to have a feedback.


-- 
Matthieu Patou
Samba Team
http://samba.org