Tidying up formatting of code, javadoc and fixing some non-behaviour-related issues
Made some class-global variables final so they're not accidentally overwritten
Adding implicit and explicit event types
Refactored a lot of duplicate code into a super class
Small change to ack/nack popup to allow displaying of design-time sample controls
Removed ImplicitPopup base class, renamed ExplicitPopup base class to UserFeedbackPopup
Added GUI layouts for Timed Abort and Simple Notification popups
Created backing classes for both the above. Only implemented SimpleNotification so far
Added code for Timed Abort popup