Update to the "cluster_info" app

[Scott Lystig Fritchie]

Hi, all.  In response to a customer problem, I've pushed a bugfix(*) to
the cluster_info app over at GitHub.  I also added a long-overdue README
file and also added a small sample report to the repository (in case you
haven't looked at the code but have wondered what all the buzz is
about).

    https://github.com/basho/cluster_info

-Scott

(*) Note that the bugfix also requires the "riak_err" application to
perform its string truncation magic.  If anyone would like to rewrite
the patch to be able to use trunc_io.erl directly (by Matthias Lang) or
some other formatting+truncation library, feel free to send a patch &
pull request to us.  :-) Both apps are covered by Apache Public License
2.0.