Do not implement a specific clone method

What we need here is a mix of deep and shallow cloning, and we
do not want to do this in a generic ol.Feature#clone() method.

src/ol/feature.js

@@ -51,20 +51,6 @@ ol.Feature = function(opt_values) {
 goog.inherits(ol.Feature, ol.Object);
 
 
-/**
- * Create a clone of this feature. Both the feature and its geometry will be
- * cloned.
- * @return {ol.Feature} A clone of this feature, with a cloned geometry.
- */
-ol.Feature.prototype.clone = function() {
-  var clone = new ol.Feature(this.getAttributes());
-  clone.setGeometry(this.getGeometry().clone());
-  clone.featureId_ = this.featureId_;
-  clone.symbolizers_ = this.symbolizers_;
-  return clone;
-};
-
-
 /**
  * Gets a copy of the attributes of this feature.
  * @return {Object.<string, *>} Attributes object.
@@ -130,7 +116,7 @@ ol.Feature.prototype.set = function(key, value) {
  * Set the feature's commonly used identifier. This identifier is usually the
  * unique id in the source store.
  *
- * @param {string} featureId The feature's identifier.
+ * @param {string|undefined} featureId The feature's identifier.
  */
 ol.Feature.prototype.setFeatureId = function(featureId) {
   this.featureId_ = featureId;

src/ol/interaction/selectinteraction.js

@@ -162,9 +162,12 @@ ol.interaction.Select.prototype.select =
         featuresToRemove.push(clone);
         delete featureMap[featureId];
       } else if (!(featureId in oldFeatureMap)) {
-        clone = feature.clone();
-        featureMap[featureId] = clone;
+        clone = new ol.Feature(feature.getAttributes());
+        clone.setGeometry(feature.getGeometry().clone());
+        clone.setFeatureId(feature.getFeatureId());
+        clone.setSymbolizers(feature.getSymbolizers());
         clone.renderIntent = ol.layer.VectorLayerRenderIntent.SELECTED;
+        featureMap[featureId] = clone;
         selectedFeatures.push(feature);
         featuresToAdd.push(clone);
       }

test/spec/ol/feature.test.js

@@ -34,24 +34,6 @@ describe('ol.Feature', function() {
 
   });
 
-  describe('#clone()', function() {
-
-    it('creates a clone with a cloned geometry', function() {
-      var feature = new ol.Feature({
-        loc: new ol.geom.Point([10, 20]),
-        foo: 'bar'
-      });
-      feature.setFeatureId('foo');
-      var clone = feature.clone();
-      expect(clone).to.not.be(feature);
-      expect(clone.get('foo')).to.be('bar');
-      expect(clone.getFeatureId()).to.be('foo');
-      expect(clone.getGeometry()).to.not.be(feature.getGeometry());
-      expect(clone.getGeometry().getCoordinates()).to.eql([10, 20]);
-    });
-
-  });
-
   describe('#get()', function() {
 
     it('returns values set at construction', function() {