Remove ol.geom.GeometryEvent

This removes geometry specific change events.  Since geometries are mere observables, we only get generic change events.  To minimize changes in other places, as a workaround, we cache geometry bounds on features.  This is not the way things should be long term, but the objective is to remove the geometry specific event.

test/spec/ol/geom/linestring.test.js

@@ -53,7 +53,6 @@ describe('ol.geom.LineString', function() {
       expect(line.getBounds()).to.eql([10, 20, 30, 40]);
       goog.events.listen(line, 'change', function(evt) {
         expect(evt.target).to.equal(line);
-        expect(evt.oldExtent).to.eql([10, 20, 30, 40]);
         expect(evt.target.getBounds()).to.eql([30, 40, 50, 60]);
         expect(evt.target.getCoordinates()).to.eql([[30, 40], [50, 60]]);
         done();