Fix weird negations when checking if operation is successful
include CppUnitTest using <>

Conflicts:
	You-DataStore-Tests/datastore_api_test.cpp
Factor out clearing of state into a method
Better test name, some explanations to test
Remove unnecessary test (already tested in internal_datastore_test)

Conflicts:
	You-DataStore-Tests/datastore_api_test.cpp
Better documentation and test name
Rename SerializedTask to KeyValuePairs