Merge branch 'release/0.84.12' into develop
Make linkedin account displayed in a human-friendly way.
Add linkedin backend to social auth.
Profile templates update.
When absolutizing an URL and it changes, update the item name if it contains the URL, else some imported articles don't get a correct title if they have an initial url that's resolved to another one during the process.
simplify a lot the create_article_from_url() helper.

- Avoid an unnecessary .save() to the DB.
- Stop overwriting imported articles title with the default one, once it's set to a human-friendly one.
- use Django's get_or_create() and avoid a lot of boilerplate code.
Fix a formating bug.
Finally fix the read created bad problem. `item` was not fresh enough.
Article → article() as much as possible.
Avoid nasty crashes in article creation with unicode(feeds). WTF??
flake8.
Dont hack item title of tweets for rendering.
Very basic display / content support for tweets. at least rendering does something now.
Fix the export.
migration: flake8.
migration: try to handle gracefully the fact that the production server is massively creating "missing" reads from already migrated articles.

Every read attribute is compared, and only true values are updated.
The new implementation will still miss dates for attributes that have been set none→on→off, but that's better than nothing.
simplify logging strings.
Simplify logging strings and avoid strainer to flood us.
simplify logging strings.
replace articles duplicates in tweet entities also.