Refresh the currently viewed page in realtime when there's change made to it

UC:

• You're viewing a page
• Someone changes the content of the page or some metadata (xobject, dates, etc)
• The viewed page content should be refreshed in realtime. The part refreshed should match what's been modified:
  • the content
  • the creator or the creation date
  • the last author or the last modified date
  • the title
  • comments (when a comment xobject is modified)
  • the history tab when the revisions are changed
  • the info tab when the displayed info is changed
• In addition, a message could also be displayed to explain that the page has been changed and the content refreshed.