Warn/catch KVM access issues
Boxes should warn user if they are not a member of the kvm
user group or have permission issues accessing KVM, which is required for virtualisation.
There are a bunch of bug reports coming in (#215 (closed), #198 (closed) , #200 (closed)) from Ubuntu users who can't run VMs because they weren't automatically added to the kvm group, but the error messages and log do not make it clear what the issue is.
Expected: Show a specific error message in UI and stderr if user does not have kvm rights or otherwise kvm is not accessible.
Edited by wesinator