title: Present a whole screen view controller over a modal view controller
body: <p>I've got an iPad app which presents a modal view controller over the main view controller. </p>
  
  <p>In the modal view controller, there is an image.</p>
  
  <pre><code>┌─────────────────────────────────┐
  │                                 │
  │      main VC in background      │
  │                                 │
  │      ┌───────────────────┐      │
  │      │  ┌─────────────┐  │      │
  │      │  │             │  │      │
  │      │  │    Image    │  │      │
  │      │  │             │  │      │
  │      │  │             │  │      │
  │      │  └─────────────┘  │      │
  │      │                   │      │
  │      │     Modal VC      │      │
  │      │                   │      │
  │      │                   │      │
  └──────┴───────────────────┴──────┘
  </code></pre>
  
  <p>I want to be able to click the image to zoom the image to the size of the WHOLE SCREEN.</p>
  
  <p>If I present the Zoom View Controller from the Modal View Controller, then it will retain the same size as the modal view:</p>
  
  <pre><code>┌─────────────────────────────────┐
  │                                 │
  │      main VC in background      │
  │                                 │
  │      ┌───────────────────┐      │
  │      │                   │      │
  │      │                   │      │
  │      │       Image       │      │
  │      │                   │      │
  │      │                   │      │
  │      │                   │      │
  │      ├───────────────────┤      │
  │      │                   │      │
  │      │     Modal VC      │      │
  │      │                   │      │
  └──────┴───────────────────┴──────┘
  </code></pre>
  
  <p>...and if I try to present the Zoom View Controller from the Main View, I will get this error:</p>
  
  <pre><code>Warning: Attempt to present ZoomViewController on MainViewController which is already presenting ModalViewNavigationController
  </code></pre>
  
  <p>So what is the correct way to present a whole screen view controller over a modal view controller?</p>