1.4.2 released

Add a MDIMessageDialogHelper class to be able to show a message dialog without having to get the application
Add an updateUI() method in the application, the menu factory, and the swing plugin to simplify the UI update
Allow to handle right clicks in the hyperlinks in the message area
Allow to use more than one MessageAreaHandlers for the MessageArea
Tweak the moment where the updateAfterGUI() method for Plugins to be sure that really all the UI (including the message area) have been created