Add acknowledgements to compute-adminguide

The bug mentioned is above removing a by-line. It turns out that
the section the by-line applies to has been updated quite a bit from
the original. So, the proposal is to remove it and add a mention
in an acknowledgements section at the end of the document.

Feedback very welcome.

fixes bug 1035675

Change-Id: I392d1c0b74fc2cb9c647e47fed44186d1faf355b
Fix bug 996970, add info about nova-manage network subcommands and --help

Change-Id: I65ed2b7e2b3b353cee484b850d1e523fa43bd56a
Merge "Add acknowledgements to compute-adminguide"