.desktop file updates

Created by: ederag

The previous Name field ("Time Tracker") was fine when it was the gnome time tracker. Since it is not part of gnome any longer, it makes more sense to add "Hamster" to the name seen in the applications menu.

Also a proposition to change the comment (not sure of this one, open to discussion). "Trackers" are often not welcome, how to convey the idea that this one is under user control ? Although there is some humor in the shadiness of "Project Hamster - your time tracker"...