ddox documentation generator

[Sönke Ludwig]

Little styling update: The module tree is now collapsible and the
default styling has been improved. Also the anchors in std.algorithm
work now (although not optimal, but that's a problem of the docs and not
the generator)

http://vibed.org/temp/phobos/std/algorithm.html
http://vibed.org/api/vibe.http.server/

Apart from the non-working links it starts to look quite statisfactory.

(Pressing F5 is necessary again, because the CSS files changed.)