[libvirt] Modified version of the libvirt-test-api wrapper

[Lucas Meneghel Rodrigues]

Hi Guannan:

I've worked on your first version of the libvirt-test-api wrapper for 
autotest. Could you please check if you like the modified version?

https://github.com/autotest/autotest/pull/230

If you do think it's fine, you can ack it, or you might take it, modify 
and resend it. On a git branch, you can do the following:

curl https://github.com/autotest/autotest/pull/230.patch | git am

And then modify and resend.

Cheers,

Lucas