isDebug now also checks melange version
To facilitate this getMelangeVersion was introduced and in order to
not show the 'Flush Cache' button a isLocal method was also added.
Patch by: Sverre Rabbelier
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