Fixed #20733 -- Typo in docs/ref/class-based-views/generic-display.txt

Thanks ijl20@ for the report.
Fixed #13721 -- Added UploadedFile.content_type_extra.

Thanks Waldemar Kornewald and mvschaik for work on the patch.
Fixed #20730 -- Fixed "Programmatically creating permissions" error.

Thanks glarrain for the report.
Fixed #17471 -- Added smtplib.SMTP_SSL connection option for SMTP backend

Thanks dj.facebook at gmail.com for the report and initial patch
and Areski Belaid and senko for improvements.
Fixed #20735 -- clarified ManyToManyField constructor doc
Merge pull request #1350 from chrismedrela/ticket20735

Fixed #20735 -- clarified ManyToManyField constructor doc
Fixed #17528 -- Documented that add() and remove() with a many-to-many relationship do not call Model.save()