Save Drafts on writing topics

As a user, I don't want to miss my topic`s text by closing tab by mistake or connection lost.
So I want to save my text during writing.

Acceptance criteria:

1. Topic`s text should be saved every 15 sec and on moving focus (including closing the page and opening other applications). So, user can close the page, open it again and see the text in Create Topic dialog.
2. Draft must be deleted when user clears message by backspace or ctrl+A and del. This must happen immediately, we don't have to wait 15 seconds.
3. User should not have special DELETE_OWN_POST permission to delete the Draft (so, every user who can create a topic can delete this draft also).
4. Draft should be deleted automatically when the topic is posted.
5. Draft should be ignored by search.
6. Acceptable number of symbols in drafts can't be more than in topics. If the text has more symbols than permitted, a warning message appears below the field with highlighting field. Text that contains 1 symbol can be saved as a draft.
7. Draft should have such attributes as date and time of last saving. When draft is saved for the first time,the text is "Saved just now"; and for the second a grey label "Saved N seconds (or minutes) ago" must be shown. If that happened more than an hour ago, then it just shows the date and time. Time in label is updated every 5 sec during 1st minute after saving, every minute - during 1st hour after saving, every hour - during 1 day after saving, then date of saving is shown.
8. User topic`s post count must not be incremented by a draft.
9. A warning popup must be shown if the draft saving didn't succeed saying: "Connection to the server was lost, please save your text locally". Message should be shown every time when connection is lost.
10. A topic title can be saved as a Draft without any message.
11. A message can be saved as a Draft with no title.
12. A poll can be also saved as a Draft. If discussion contains a poll items and/or poll title - it should be saved too.
13. User can create Discussion draft with poll/poll options, then close this one and open draft in Q&A/CodeReview creation page. The title topic and a message body will be saved in Drafts.
14. User can create Discussion draft with poll/poll options, then close this one and open draft in Q&A/CodeReview creation page, close it and open as a Discussion topic creation - poll options, poll title and a message body should be shown.
15. Additional checkboxes and poll end date are not saved.
16. Story should be implemented for discussion topic, Q&A and Code review (not comments, just topic)
17. Drafts for topic should not be available in Recent Activities and Topic without answer.
18. If a User gets logged out, he or she receives a message "You logged out'.
19. User is allowed to have only one Draft.
20. Draft is not attached to the any branch.
21. All fields should have validation only for max length and max items count in poll options list.
22. If User creates topic draft and leave topic creation page - he/she can see his/her draft when he/she opens new topic page again.

Justification on when to save Draft:

• It's not likely that user removes the content and then he accidentally leaves the page. This case is not realistic. Therefore we respect all the actions of the user as intentional and simply save Topic Draft once in period.
• Topic Draft must be also saved when user clicks somewhere outside of the text area - e.g. for cases when he closes the tab accidentally or presses Back or Forward.
• Also it's decided to remove Topic Draft right away when user removes the whole content because otherwise the content will be there when he removes. Even if he intentionally removed it.

Known bugs