[Pharo-project] Added a 3.0 milestone tag

http://code.google.com/p/pharo/issues/list?can=2&q=milestone%3D3.0&colspec=I... This is for making a list of things to be done *not* for 2.0 but later. E.g. removing URI or cleaning up the use of the low-level DisplayObject animation code by Morphic Drag-n-Drop