Enable rebooting in the client lib and cli

The client library should be able to request that a node be rebooted by
passing the "reboot" state to the API. This functionality should be
exposed in the CLI as well.

This depends on commit Ic13c046c621211d9c1533325812955233441d2da

Change-Id: I7954c02a3b5fd8f6caa574fd581f2ae3b0c3d422
Merge "Enable rebooting in the client lib and cli"