PowerOn_Task and AnswerVM demo

Demonstrates how to deal with a PowerOn_Task that's interrupted by
the need for an AnswerVM call.
Merge pull request #58 from hartsock/power_on

power_on a VM and how to deal with a VM question
comment: virtual_machine_power_cycle_and_question

There is an erroneous comment in virtual_machine_power_cycle_and_question.py