Hopefully fix json caching issues in IE7.
Will wait for Lennie to confirm if it works correctly now.
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