Bug 840887 - New OS.Constants constants. r=khuey
Bug 840887 - Fix behavior of DirectoryIterator when the directory doesn't exist - Unix version. r=froydnj
Bug 840887 - Fix behavior of DirectoryIterator when the directory doesn't exist - Windows version. r=froydnj
Bug 840887 - DirectoryIterator.prototype.exists - asynchronous version. r=froydnj
Bug 840887 - Test the behavior of DirectoryIterator when the directory doesn't exist. r=froydnj