Now clicking cancel button returns user to previous page. Fixes issue 569.
If you don't want that behaviour you can define cancel_redirect and user will be redirected to given url on "Cancel" button click instead of redirecting to previous page.
Patch by: Daniel Hans & Pawel Solyga
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