Merge pull request +16019 from c9/fix-firefox-xhr-errors

without content type firefox tries to parse xhr result as xml

plugins/node_modules/vfs-http-adapter/restful.js

@@ -315,7 +315,7 @@ module.exports = function setup(mount, vfs, mountOptions) {
                     command = vfs.symlink;
                     options.target = message.linkTo;
                 }
-                else if (message.metadata){
+                else if (message.metadata) {
                     command = vfs.metadata;
                     options.metadata = message.metadata;
                 }
@@ -324,6 +324,7 @@ module.exports = function setup(mount, vfs, mountOptions) {
                 }
                 command(path, options, function (err, meta) {
                     if (err) return abort(err);
+                    res.setHeader("Content-Type", "text/plain");
                     res.end();
                 });
             });