ANN: anaconda yum migration testing

[Paul Nasrat]

Over the next week as part of the work to try get anaconda installs
using yum I'm going to switch over to yum by default:

* nfs installs will use yum as a back end
* nfsiso installs will not be available

Other install methods will fall back on the old method of
depsolving/installing

Later in the week http/ftp installs will move to using yum as a back
end. Some work in install speed optimisation will be needed but at the
moment we are focussed on getting it working without.

Paul