util: Add ConnectAndWait helper

It is used by both vmw and vbox. Introduce a helper.
Also increases the time to wait since it might take longer time when
user starts VMware for the first time.

Signed-off-by: Asias He <asias@cloudius-systems.com>
cmd/delete: Stop instance before delete it

Signed-off-by: Asias He <asias@cloudius-systems.com>
Merge pull request #85 from asias/connect_and_wait

Connect and wait