Moved getRealVideoSink(), record() and stopRecording() methods up from
SmartTimelineBin to SmartBin.
* pitivi/playground.py:
Documentation cleanup.
Make relevant functions return False for failures.
Added _handleError() and _handleWarning() methods for analyzing the
error/warning information and creating user-friendly messages.
* pitivi/utils.py:
New function bin_contains() in order to figure out if an element is in
a bin recursively.
* pitivi/ui/mainwindow.py:
Only display one ErrorDialogBox at a time
* pitivi/ui/viewer.py:
Improve aspect ratio handling


git-svn-id: svn+ssh://svn.gnome.org/svn/pitivi/trunk@751 d3729300-e425-0410-8a4c-d956edccc248