Image name conflict if using vagrant on the same system as vagrant-builder

[vvaldez]

From purpleidea: "if you use vagrant-builder to build an image named say "rhel-7.0" and then you go to import that into vagrant under the same name, there will already be a storage entry for that name from the build, so they clash. so i currently manually remove the storage entry from the build."

[purpleidea]

+1 ... This probably needs confirming, because I remember this happened, and it's probably easy to figure out what commands need running to unregister the image from libvirt at the end of the build cycle. I've been randomly clicking in virt-manager to fix this I think.

[purpleidea]

FWIW the work around is mentioned in the bottom of this commit: e99f888 if someone wants to reproduce to be sure, and submit a patch to do this automatically, that would of course be fine :) cheers!