[packagekit] Support CD/DVD media as package sources in yum backend

[مؤيد السعدي]

Hello,

I have took a look into pirut source code and noticed how simple it's to
implement this, thanks to the API change that added
backend.error(ERROR_MEDIA_CHANGE_REQUIRED, ..etc.

https://bugzilla.redhat.com/show_bug.cgi?id=435625
https://fedoraproject.org/wiki/Features/MediaRepo

I'm going to implement this, any suggestions ? was any one planing to do
this ?
I'm going to try it with HAL then replace it with devicekit