Introduce Avocado journal replay utility

A command line utility that can read a test journal (when the test
is run using '--journal' (and thus the journal plugin), and can
send all the test activities recorded to a central Avocado Server.

Signed-off-by: Cleber Rosa <crosa@redhat.com>
Merge pull request #53 from clebergnu/journal-replay

Introduce Avocado journal replay utility