Autosave draft

Completed with:

- [x] Auto-Save on Posts.

- [x] Implement Save-As-Draft Button on Create and Edit post

- [x] 'Drafts' tab in menu bar

- [x] Display Drafts of the current logged-in User.

- [x] on Edit draft - publish post or save-to-draft

- [x] No Activities for Draft.

- [x] Draft should not be consider in Top3 contributors post count.

- [x] Drafts Tags should not be included in Tag-cloud.

- [x] Draft should not be shown in search results.

- [x] Add and Update Specs for the above features.

Can you please review the code changes? and let me know if any further modifications are required.

Thanks.