The DUB package manager

[Sönke Ludwig]

> You might want to list all the dependencies needed for dub or
> distribute them in a zip.
> 

They are in the .zip now and I listed the dependencies on the download
page. Sorry, the distribution stuff is still very much ad-hoc ATM. I'll
make some installers once the build process is automated.

> Ah I didn't spot the download link http://registry.vibed.org/download
> 
> I guess this could be made more visible by adding a link to the
> download page from the github repository, and maybe putting the { *
> Using DUB * Download * Publishing packages * Helping developme }
> section at the top instead of the bottom.

There now is a link on the github page + a note for non-Windows that
libevent/libssl are needed. I also added a short sentence how to build
by hand. The dependencies will also likely change to just libcurl at
some point with a make file or something to make bootstrapping as simple
as possible.

I also agree regarding the navigation links. The page layout will have
to be extended a bit to handle more packages anyway (pages, search
function, possibly categories) so I'll keep it as a TODO item for a few
days and then do both at once.