Added copyTasks method to IDonResponse interface and implemented in DonResponse.
Added import relevant import to IDonStorage.
Implemented findTask for string searches.
Added editTask, deleteTask, toggleStatus methods that take in a name. They are all essentially wrappers that use the string version of findTask to call the ID version of the corresponding methods. These are not called by runCommand yet.
Added findTask that uses a given date.
runCommand now calls the edit/delete/mark methods that use a title as the search option.
runCommand now calls the findTask with the date parameter.