Window level higher than normal

When displaying the Toast under status bar the windowLevel is set to `UIWindowLevelNormal`. However, this is not fully correct because this window is on top of the main application window. When using this library with others like `SVProgressHUD`, they have problems identifying the proper place to insert themselves. Just adding a small amount (+1) works and configures this window on proper level (above the app).
Merge pull request #79 from junjie/fix-dismiss-all-animation

Fix bug where +dismissAllNotifications: does not respect the animated flag
Merge pull request #70 from angelolloqui/master

Window level higher than normal
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