Issue 5277: Display @import rule media queries and allow editing them

Steps to reproduce

  1. Open Firebug
  2. Switch to the CSS panel
  3. Select issue5277.html from the Location Menu
    @import "issue5277.css" screen and (min-width: 400px); should be listed inside the panel
  4. Resize the browser window, so that the content width is between 400 and 800 pixels
    ⇒ The <div> above (#element1) should be green
  5. Click the media query of the rule
  6. Change 400px to 800px
    ⇒ The <div> above (#element1) should now be blue
  7. Leave inline editing by clicking somewhere outside the editor
  8. Resize the browser window, so that the content with is greater than 800 pixels
    ⇒ The <div> above (#element1) should be green again

Expected result