ADD: we have now a data transfer object to transport information from
the controller to the view
ADD: new methods called by the controller
ADD: there is a method, which is called by the MainFrame.
REM: some functions to calculate the filesize
CHG: the method textUpdate has been renamed into documentUpdate, it does
not longer user events
REM: all references to the model class has been removed, it is now a
Passive View
MOV: some functionality from the view has been moved into the controller
to have a passive view.
CHG: the MVC cascade has been changed, the view constructor doesn't
longer need any parameter
CHG: the controller class is now a presenter according MVP (Passive
View) - see Martin Fowler
CHG: the action constants are now part of an enum
ADD: the model class ha now an interface