Dispatch 'done' event after '_pollAgain'.

This allows 'close' called from a 'done' handler to cancel the upcoming
reconnection. Otherwise '_pollTimer' will get reset after the handler.

Author: daniel-bryant

src/EventSource.js

@@ -116,9 +116,9 @@ class EventSource {
           this._handleEvent(xhr.responseText || '');
 
           if (xhr.readyState === XMLHttpRequest.DONE) {
-            this.dispatch('done', { type: 'done' });
             this._logDebug('[EventSource][onreadystatechange][DONE] Operation done.');
             this._pollAgain(this.interval, false);
+            this.dispatch('done', { type: 'done' });
           }
         } else if (xhr.status !== 0) {
           this.status = this.ERROR;