Merge branch '417-lidmaatschapsdata-van-een-commissie-kunnen-buiten-het-bestaan-van-een-commissie-vallen' into 'master'

Force start and end date to be within comittee start and end date

Closes #417

See merge request !561

Clarify licencing situation

Closes #505

See merge request !568

Closes #505

Fix mailinglist apihash

See merge request !567

Properly gather verbatim mailinglist addresses

See merge request !565

Joost Rijneveld authored Sep 14, 2017 and Sébastiaan Versteeg committed Sep 14, 2017

Previously the output of this function was a mixed list of strings
and VerbatimAddress objects. It worked because those had a __str__,
but in the new API they must be literal strings.

Change TinyMCE4 plugin

See merge request !563

Improve TinyMCE4 settings

See merge request !551

Move notification email of vacancies to a management command instead of using a…

See merge request !559

Only send queue mail when registration really is a member

See merge request !560

Move notification email of vacancies to a management command instead of using a non-secured HTTP endpoint

Set expiration_mail_sent in partners default to False

See merge request !558

Fix problem when event has no max participants limit

See merge request !557

Fix events admin button to set all present

See merge request !553

no longer count members twice in statistics

Closes #496

See merge request !554

Do not send members duplicate emails about their membership

See merge request !555

List each member only once in Registration admin

Closes #484

See merge request !556

Previously `Member`s with multiple `Membership`s were listed

It might be the case that members with multiple `Membership` objects are sent
duplicate emails about their expiring memberships.

Members with multiple `Membership` objects were counted twice in the statistics.
If a Member has multiple `Membership` objects and a queryset filters on
`user__membership` the Member will appear multiple times in the result, by doing
a `.distinct()` these duplicates are removed.

Export email addresses of event attendees

Closes #431

See merge request !550

Add basic table with information on automatically generated mailinglists to admin

Closes #476

See merge request !547

Make sure the mentor mailinglist uses the next lecture year from January till…

Closes #486

See merge request !548

Make sure the mentor mailinglist uses the next lecture year from January till September, otherwise the recipients are those of the intro of last year