add release note that OpenStack should be used on a protected network

[Jamie Strandboge]

Much of OpenStack is hard-coded to use http instead of https. Of particular interest is keystone which is the identity service for OpenStack. https://wiki.ubuntu.com/PrecisePangolin/ReleaseNotes/UbuntuCloud should state that accessing OpenStack over an unprotected network may expose credentials and other information. This is true (at least) when:
* keystone is on a separate server from the other OpenStack components
* horizon (the OpenStack Dashboard) is on a different system than keystone
* users access OpenStack remotely
* users access horizon (the OpenStack dashboard) over http

Adding horizon and keystone tasks.

[Dave Walker (davewalker)]

Release Note Added:

* The default install of Openstack should be used on a protected network, as many components use http (non-SSL) as a transport, and therefore subject to security concerns. This can be mitigated by post install customisations.

https://wiki.ubuntu.com/PrecisePangolin/ReleaseNotes/UbuntuServer

[Dave Walker (davewalker)]

@dstrand: Please comment if you want further additions.

[Jamie Strandboge (jdstrand)]

Keystone cannot be mitigated by post install customizations AFAIK. Horizon can be delivered through standard https.

[Adrien Cunin (adri2000)]

Why do we keep horizon and keystone tasks?

By the way, I think it's possible to mitigate this issue in Keystone using Apache. See http://adam.younglogic.com/2012/04/keystone-httpd/ to set it up and be able to use https:// for Keystone.

[James Page (james-page)]

Keystone and Horizon are the default external access routes to OpenStack.

The default package configuration still uses http.

Added to quantal release notes.