Application-centric interface for Update Manager

My goal is to improve several parts of Update Manager's interface to bring it in line with how package management is starting to look, on the desktop, in Debian and many derivatives. My project stems from MPT's specification at wiki.ubuntu.com/SoftwareUpdates.

Armed with that specification, I want to change Update Manager to provide an application-centric view of updates, reducing some of the clutter and complexity that can trouble users when they encounter updates on Debian systems. By focusing on applications, we can provide a friendlier experience for users who are less comfortable with package management.

This does feel a little out of place, but Update Manager _is_ focused on Debian, and it is an important part of Debian's GNOME desktop. I believe improving this component will improve the experience people have with package management in Debian itself, as well as the rich population of distributions that are built on Debian. This project will certainly be spreading its love to many different places, and for that to work as well as possible I think it's important to work on this somewhere close to the roots.