Change a few errors to report names, not UUIDs
Change a few errors to report names, not UUIDs

Node/Node group name is much easier for humans to read.

Signed-off-by: Brian Foley <a00e555871a6a538e97f8c44307104c884f8e869@google.com>
Reviewed-by: Viktor Bachraty <a13ea37fcfcda126dc54f94389ded93f402eee93@google.com>

mbakke/ganeti,mbakke/ganeti,ganeti/ganeti,ganeti/ganeti,yiannist/ganeti,onponomarev/ganeti,mbakke/ganeti,yiannist/ganeti,andir/ganeti,onponomarev/ganeti,andir/ganeti,yiannist/ganeti,andir/ganeti,ganeti/ganeti