avocado.utils.remote: Changes to the .run() method

Make the run() method to return a CmdResult object,
to make it symmetrical to the process.run() result.
Also, turn on logging of outputs for commands executed
on remote connections.

The reason why we want to do that is to increase the
debugging output we have for commands executed over
the fabric SSH connections. This way we can obtain
better, richer outputs in test logs that use our
fabric wrappers.

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
avocado.test: Save whiteboard to a file in the results dir

For convenience, save the contents of the whiteboard
into a file 'whiteboard', inside the test results.

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
docs: Document new save whiteboard convenience feature

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
selftests/functional: Add whiteboard creation test

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
selftests/unit: Add unittest for whiteboard save

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
Merge pull request #232 from lmr/remote-changes-sprint14

avocado.utils.remote: Changes to the .run() method