call awakeFromNib super implementation

[davidfuzju]

hi, I am sorry to bother you with such a small commit. Recently I write a class to implement custom relationship segue, SMBCustomRelationshipSegue, and I use your awesome reside menu as a example to show how to connect custom relationship just in storyboard, everything works fine until I want improve my implementation to use awakeFromNib method instead of viewDidLoad Method. I found:

#if __IPHONE_8_0
- (void)awakeFromNib
{
    if (self.contentViewStoryboardID) {
        self.contentViewController = [self.storyboard instantiateViewControllerWithIdentifier:self.contentViewStoryboardID];
    }
    if (self.leftMenuViewStoryboardID) {
        self.leftMenuViewController = [self.storyboard instantiateViewControllerWithIdentifier:self.leftMenuViewStoryboardID];
    }
    if (self.rightMenuViewStoryboardID) {
    self.rightMenuViewController = [self.storyboard instantiateViewControllerWithIdentifier:self.rightMenuViewStoryboardID];
    }
}
#endif

because your implementation did not call awakeFromNib's super's implementation, my lib could not to hook the method to work well. so I created this pull request to figure out why not call the super implementaion as usual. My lib works well with your lib under iOS 7.X.