f23 proposal: install muon-discover (software center) by default

[Rex Dieter]

Polished up muon-discover, and fixed an appstream bug today, so I think it's 
time to seriously consider adding it to the fedora 23 kde spin.  For those 
not familiar with it, it's approximately kde's version of gnome-software, an 
application-centric software center.  In particular, it's not a package 
manager (that nitch will continue to be served by apper).

https://bodhi.fedoraproject.org/updates/FEDORA-2015-77b834245b

I'm hoping to use lazy consensus here, any objections?

-- Rex