Merge lp://staging/~sinzui/bzr-gtk/fix-threads-icons into lp://staging/bzr-gtk/gtk2

Fix running threads and missing images reported by test suite.

added:
  tests/test_avatarsbox.py
modified:
  avatarproviders.py
  avatarsbox.py
  tests/__init__.py
  tests/test_annotate_config.py
  tests/test_revisionview.py

Setup the window before the working directory is changed, or patch the window
to use a fake implementation of icon_path that know where the icons are.
  tests/test_annotate_config.py
  tests/test_revisionview.py

AvatarDownloaderWorker and its queue were leaving thread behind.
* I refactored the code to just use __stop and removed __end_thread.
* The fix for the worker was to ensure that stop was called during the
  widget's destroy event.
* The queue was troublesome because the worker's run() method was blocking on
  it--join() would never return.
* The fix was to not start the thread until something was queued,
* The stop() method dequeues the avatars so that the queue knows it
  is finished.
* The run() method uses a non-blocking call to something from the queue.
  The loop recovered from the Queue.Empty error.
  avatarproviders.py
  avatarsbox.py
  tests/test_annotate_config.py
  tests/test_revisionview.py

ADDENDUM: The __eq__ method was checking the widget's name attr
(which is always None) instead of the username attr.
  tests/__init__.py
  tests/test_avatarsbox.py
  avatarsbox.py