avocado.virt.test: Assemble a basic VM command line at setup

Instead of letting the test writer to mess around with creating
a basic QEMU command line, create a basic VM command line, and
let the users with the task of starting it up/shutting it down.

The resulting object can be accessed using self.vm.

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
avocado.virt.qemu.machine: VM method name changes

The summary of the changes:

* launch() becomes power_on()
* shutdown() becomes power_off()
* setup_remote_login() becomes login_remote()

The name changes were discussed upon Sprint 13 review,
it basically boils down to more elusive, familiar names.

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
avocado-virt: Bumping release to 0.1.3

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
Merge pull request #3 from lmr/api_simplify_sprint13

API Simplify Sprint 14