bare-metal install network setup does not check if configured provisioning ip range is sufficient

[parity3]

The system services will fail to start when there are more zones than can be provisioned in the initial sdc 7 setup. Originally I elected for admin as 10.2.1.251-255 and external is 10.2.1.240-248 on the same subnet, not knowing that each zone would need to get its own IP.

It would have been nice to have this checked earlier. Something weird happened where zones were allocated in an incremented network of 10.2.2.0/24 IPs and then was unable to route to them.

After restarting the setup and choosing 100-175, 175-250 ranges the setup process and sdc-healthcheck finished successfully.

[numericillustration]

Also the installer doesn't sanity check the valid subnet size so if you supply say a /27 it will accept it and fail at init in napi with http://pastebin.com/vXWJP93a from somewhere in here https://github.com/joyent/sdc-napi/blob/47ab1da00612ff5e319d9abbfb036da503b85fb6/lib/models/network.js#L806-L815