fix(server): launch browsers when file_list is ready

If we have a lot of files and a fast starting browser (PhantomJS),
the browser might try to connect to the web server before the
server is ready to reply, causing the connect mechanism to time out.
Make sure to wait until fileList.refresh() is complete before starting
the browsers.

lib/server.js

@@ -34,7 +34,7 @@ var start = function(injector, config, launcher, globalEmitter, preprocess, file
   var filesPromise = fileList.refresh();
 
   if (config.autoWatch) {
-    filesPromise.then(function() {
+    filesPromise = filesPromise.then(function() {
       injector.invoke(watcher.watch);
     }, function() {
       injector.invoke(watcher.watch);
@@ -61,15 +61,21 @@ var start = function(injector, config, launcher, globalEmitter, preprocess, file
   // Some browsers did not get captured.
   var singleRunBrowserNotCaptured = false;
 
-  webServer.listen(config.port, function() {
-    log.info('Karma v%s server started at http://%s:%s%s', constant.VERSION, config.hostname,
-        config.port, config.urlRoot);
-
+  var launchSingleRunBrowsers = function() {
     if (config.browsers && config.browsers.length) {
       injector.invoke(launcher.launch, launcher).forEach(function(browserLauncher) {
         singleRunDoneBrowsers[browserLauncher.id] = false;
       });
     }
+  };
+
+  webServer.listen(config.port, function() {
+    log.info('Karma v%s server started at http://%s:%s%s', constant.VERSION, config.hostname,
+        config.port, config.urlRoot);
+
+    // Wait until fileList.refresh() is done, or else we might
+    // not be ready to reply to the browser's capture request.
+    filesPromise.then(launchSingleRunBrowsers, launchSingleRunBrowsers);
   });
 
   globalEmitter.on('browsers_change', function() {