[atomic] Fedora 22 TC3

[Colin Walters <walters verbum org>]

https://lists.fedoraproject.org/pipermail/test/2015-May/126419.html

links to the current test compose.  Notably there is an F22 Atomic
cloud image, installer ISO (and installation tree).  The next compose
should have Vagrant (libvirt and virtualbox).

The installer and cloud image work for me in basic testing.

Also, I updated
https://fedoraproject.org/wiki/Fedora_22_talking_points
with some changes that have happened since Fedora 21.

Please feel free to report issues here or in Bugzilla, and any
suggestions for the talking points appreciated!