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
avocado.plugins.datadir: Trim docstring

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
Merge pull request #54 from ruda/master

avocado.plugins.manager: Skip loading bad builtin plugins.
Fix test execution when running in standalone mode.

Fix errors:

* AttributeError: 'NoneType' object has no attribute 'unique_id'
* AttributeError: 'NoneType' object has no attribute 'keep_tmp_files'

When running tests standalone, like:

python tests/sleeptest/sleeptest.py

Signed-off-by: Ruda Moura <rmoura@redhat.com>