Add task and iterative_task decorator
Also add getBatchOfData method to the base logic and tasks logic
module.
Reviewed-by: Sverre Rabbelier
Coverage: code coverage testing for PythonCoverage.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 standardlibrary to determine which lines are executable, and which have been executed.For more information, see http://nedbatchelder.com/code/modules/coverage.html