MTStatusBarOverlayiOS自定义状态栏

MTStatusBarOverlay 是一个定制的 iOS 状态栏，用于覆盖系统默认的状态栏，类似 Reeder, Evernote and Google Mobile App

示例代码：

 MTStatusBarOverlay *overlay = [MTStatusBarOverlay sharedInstance];
 overlay.animation = MTStatusBarOverlayAnimationFallDown;  // MTStatusBarOverlayAnimationShrink
 overlay.detailViewMode = MTDetailViewModeHistory;         // enable automatic history-tracking and show in detail-view
 overlay.delegate = self;
 overlay.progress = 0.0;
 [overlay postMessage:@"Following @myell0w on Twitter…"];
 overlay.progress = 0.1;
 // ...
 [overlay postMessage:@"Following myell0w on Github…" animated:NO];
 overlay.progress = 0.5;
 // ...
 [overlay postImmediateFinishMessage:@"Following was a good idea!" duration:2.0 animated:YES];
 overlay.progress = 1.0;