Autosave articles every 5 seconds as drafts to avoid loss of data

This is one of our top requested feature and one of the biggest frustration the users are facing when they mistakenly close the tab or navigate away from the page! This changes two things:

* Clicking Create will initialize and store an empty article and the user will update that article afterwards.
* When a user wants to update an already published article, they will be warned that the article will be moved to draft and they can publish it again once done.
* Dropped the save button.