RTE breaks wiki.editcomment.mandatory=1: Summary popups interrupt editing

I did the following changes:

• Use a reasonable initial title when title is mandatory, in order to not block auto-save (unless the users clear themselves the title field, but then it's on purpose so they will have to fix it)
• Use a default version summary comment when auto-saving from real-time editing ("Auto-saved during real-time collaboration"). This way auto-save is not blocked. Save by the user, either using a button or the shortcut keys is still blocked until they provide a change summary (i.e. either through the change summary modal or alert / popup).
• Made the Done button act like "Summarize & Done" when version summary is mandatory. The idea is that you have auto-save during real-time editing (which doesn't ask for a summary), but at the end, when leaving, you need to provide that summary. The downside is that:
  • the Done button always asks for a summary, even if there are no changes. This is consistent with the behaviour of the old Save buttons; the consequence is that, with a provided summary, the Done button is going to always create a new version
  • Without a Cancel button, you'll have to either use the Cancel shortcut key (Alt+C) or some link on the page (breadcrumb / navigation panel) to return to view mode without creating a new version (as long as version summary is mandatory)
• Validate the version summary in the "Summarize Changes" modal (e.g. check if it's mandatory)