Check if timeline exists and when somebody tries to edit non existing timelime display error message. Add TODO regarding error message customization for Timeline. Add support for calendar widget in timeline for both gsoc and ghop programs (gsoc was hardcoded before).
Patch by: Pawel Solyga
Review by: to-be-reviewed
Coverage: code coverage testing for Python
Coverage.py is a Python module that measures code coverage during test execution.
It uses the code analysis tools and tracing hooks provided in the Python standard
library to determine which lines are executable, and which have been executed.
For more information, see http://nedbatchelder.com/code/modules/coverage.html