Tags

* Fixed migration dependencies
* Fixed id conservation in group migration
* Fixed flake8 and tests

release-october includes:

* galleries have a nice lightbox
* show main nav in menu on mobile devices
* allow users to configure mail notification for outside contacts
* signed-in users who create a group become a member automatically
* groups are sorted alphabetically
* lists in content don’t require leading newline
* groups can be referenced with @ even if it includes special chars
* show 5 instead of 3 events in calendar preview
* email quotes now contain the correct ">" char instead of weird ">"
* comment mail notifications reference the individual comment directly
* users with old browsers are notified that we don’t support them
* a carousel for group images has been implemented
* add info during signup that email address are not published anywhere

fixed tickets:
 #235, #234, #233, #229, #227, #225, #221, #218, #217,
 #210, #209, #206, #204, #203, #202, #200, #198, #197,
 #193, #187, #186, #184, #149, #127, #232, #199