Refactor(UserAccountDAO): move to package database.
Refactor(PersistentUserAccountDAO): move to package database.
Refactor(SessionDAO): move to package database.
Add(UserSession): methods createSession and resume.
Refactor(SessionDAO): method createSession directly accepts the hashed session id as its second argument.

Refactor(UserSession): method createSession generates the hashed session id.
Add(CalendarUtility): an implementation of CalendarUtilities.
Refactor(CalendarUtilities): rename method timestampSum to timestampAddMinutes.
 Refactor(timestampAddMinutes): change type of second parameter to int and rename it to 'minutes'.
Add(HashingUtility): an implementation of HashingUtilities.
Refactor(PersistentUserAccountDAORule): database autocommit is set back to true after the test data is loaded.
Add(PersistentSessionDAO): Implementation class of SessionDAO interface.
Implement(getUserFromSession).