Move wait time to httploop_result.

httploop_result is the Lua hook that's guaranteed to be called after
every request.  download_child_p isn't.
Update README.md

zlib-devel is needed; otherwise, wget-lua won't produce warc.gzs.
Merge branch 'move-wait' of https://github.com/yipdw/hyves-grab into yipdw-move-wait
Merge remote-tracking branch 'origin/master' into develop
Bumps version 20131120.01, closes #2.