Set the srs name when writing GetFeature

Also make clear that srsName is only optional for WFS 1.0.0.

src/ol/parser/ogc/filterparser_v1.js

@@ -648,6 +648,6 @@ ol.parser.ogc.Filter_v1.prototype.setFeatureType = function(featureType) {
 ol.parser.ogc.Filter_v1.prototype.setSrsName = function(srsName) {
   this.srsName = srsName;
   if (goog.isDefAndNotNull(this.gmlParser_)) {
-    this.gmlParser_.srsName = this.srsName;
+    this.gmlParser_.applyWriteOptions({}, {srsName: srsName});
   }
 };

src/ol/parser/ogc/wfsparser_v1.js

@@ -47,6 +47,9 @@ ol.parser.ogc.WFS_v1 = function(opt_options) {
         if (goog.isDef(options.maxFeatures)) {
           node.setAttribute('maxFeatures', options.maxFeatures);
         }
+        if (goog.isDef(options.srsName)) {
+          this.setSrsName(options.srsName);
+        }
       }
       for (var i = 0, ii = options.featureTypes.length; i < ii; i++) {
         options.featureType = options.featureTypes[i];