title: Draft.JS: the proper way to detect content change
body: <p>There is <a href="https://facebook.github.io/draft-js/docs/api-reference-editor.html#onchange" rel="noreferrer">onChange</a> event, but it fires also when carret moves or navigation (arrows etc) button being pushed.</p>
  
  <p>I want to detect if <strong>content</strong> was changed. Basically i need to detect this only once when the very first change occur. The dumb way "compare content" may work here, but this is an anti-pattern because this task is too resources-expensive.</p>