Code review comment for lp:~ltrager/maas/reset_node

I've added a set_initial_networking_configuration and a restore_default_configuration operation in place of reset for both machines and devices. restore_default_configuration resets networking and storage options to default on machines, if there is anything else it should be resetting please let me know. For devices restore_default_configuration is the same as set_initial_networking_configuration, I added it to devices so MAAS has a consistent operation to reset all fields.