Missing images from Documentation

[Dirk Hohndel]

"Lubomir I. Ivanov" <neolit123 at gmail.com> writes:

> i've just checked the new documentation.
> nicely done!
>
> there seem to be some images missing in there e.g.
> /images/icons/warning.png
> /images/icons/callouts/*
>
> perhaps these should be committed as well.

Those come from asciidoc. I need to double-check the licenses to make
sure that I can just add them :-)

/D