Implement Graphical View for annotations

This is a request from a user, see "http://ugene.unipro.ru/forum/YaBB.pl?num=1304459187".

"I think it would be awesome if you had some sort of view option that was like a graphics view for annotations. So for example, you would see your sequence, and you would be able to adjust the location of certain annotations, up or down, and then have notes pointing to each annotation. If you're familiar with Lasergene's products, specifically "sequence builder", there is a view option called "Linear map", where you can do just this. Then you can zoom and in and out. It creates a nice way to very quickly have an excellent schematic for publications or discussions in Powerpoint."