VM start command race condition

[twstokes]

When a VM is started with the hostmgr start command, a race condition exists where:

1. The VM is requested to be started
2. The server (hostmgr-helper) returns that the VM has started
3. The client (hostmgr) then grabs the IP (if told to) of the new VM and confirms that SSH is available

It's possible for the VM to be removed between steps 2 and 3 if an outside call is made to hostmgr vm stop. An improvement could be for the second step to return this information upon creation synchronously and remove step 3.