There is a need of nova delete all vm

Currently, For the command line, novaclient only support one by one deletion or list of VMs , which is frustrating when there is a lot of vms to delete.
So, We want to add new cli command "nova delete-all" for vms.
and nova delete-all --exclude vm1 vm2 .. /* which delete all VMs except those VMs we want to guard

Also following enhancement can be done

For example:
If we want to delete all the VMs from a particular compute host:

[1] nova delete-all --host compute1

[2] nova delete-all --host compute1 --exclude vm1, vm2