How can I hide resource forks and other special files in a workspace in Xcode 4's project navigator?

问题

I've noticed the resource forks (._filename) and other hidden files like ._.DS_Store are shown in the project navigator when working on a "Workspace" project (Ruby).

How can configure Xcode 4 to not display these files in the project navigator?

来源：https://stackoverflow.com/questions/5371963/how-can-i-hide-resource-forks-and-other-special-files-in-a-workspace-in-xcode-4