title: UITableView - insert rows with animation issue
body: <p>I have strange problem. In my application i have UITableView with list o comments. Cell is composed with UIImageView (background) and UITextView. For one-line comments i'm changing size (frame of UIImageView) of the background to fit the size of the text (it's called in cellForRowAtIndexPath:). It works fine for scrolling etc but when i'm changing size of the table with animation (UIView animateWithDuration:), new rows are displayed at the top and user can notice that frame of the background is also changed with animation.
  Any idea how to prevent animating this background image?</p>
  
  <p><img src="https://i.stack.imgur.com/d0c0Y.png" alt="enter image description here"></p>