project: Add the aspect_ratio dynamic property
timeline: Avoid calling a callback method directly
timeline: Get rid of method used in a single place
timeline: Test directly the element, not its parent
timeline: Be more strict when a timeline element is added
tests: Allow the tests to be run by frameworks like nosetests
tests: Simplify the no color logging setting
loggable: Make sure funcname is always set
loggable: Pass the correct file path when calling handler
loggable: Reuse the code calling the handlers
loggable: Fix the getFileLine return value when there is an error
tests: Resurrect test_log
tests: Update the ProjectManager unittests

Also moved them to test_project.py so they can be found easily since the
ProjectManager class is in project.py.
mainwindow: Reuse in_devel from configure

Also fix its usage.
mainwindow: Make the version display more robust in the about window

Also add a unittest for the latest version logic and
moved the Pitivi tests to test_application.py because
that's the module where the Pitivi class resides.
tests: Move the system module tests to test_system

Also some cleanup in the file headers.
tests: Rename test_base.py because it's not a test
render: Allow the render progress dialog to close the desktop notification

This got broken in 38861f742af4ce115c9265f3e7c85d8ea0f17111
Fix the dogtail tests