iOS: Lock change orientation of Controller. (Having enabled two orientations in the project summary)

gistfile1.m

// Portrait
- (NSUInteger)supportedInterfaceOrientations {
    return UIInterfaceOrientationMaskPortrait;
}

// Landscape
- (NSUInteger)supportedInterfaceOrientations {
    return UIInterfaceOrientationMaskLandscape;
}