Modified DonLogic to use Java's Logger class for logging.
Added toString to DonPeriod.java
Changed the accessibility of the tasks field in DonStorage to protected so that it can be accessed by subclasses (currently used for testing).
Changed DonLogicTester to use the new DonStorageStub (not really a stub but an alternative) that has the ability to save to a specified path.
Moved DonLogic creation code in DonLogicTester to a new @BeforeClass method (initLogic) and test cleanup code to removeTestFile.