JavaDoc class SubscriptionExistsAlreadyException and its partner function throwIfSimilarSubscriptionExists
JavaDoc class UnknownSubscriptionException
JavaDoc function storeNewSubscriptionAndCommit.
Fix missing initializeTransient(): 
- throwIfSimilarSubscriptionExists() will call member functions of the Subscription already.
JavaDoc functions subscribeToIdentityAttributeList, subscribeToIdentityList, subscribeToTrustList, subscribeToScoreList.
Upgrade TODO of removing debug code to FIXME since we should get rid of it before deploying the code. Also clarify this more.
Fix synchronization of debug code:
- While sending out the InitialSynchronizationNotification, it must be guaranteed that the WOT does NOT get modified in between.
JavaDoc function unsubscribe()
JavaDoc function getAllSubscriptions()
JavaDoc function getSubscriptions()