Use more specific exceptions and include context

See merge request !618

Fix MemberMiddleware in the API

See merge request !616

The MemberMiddleware was broken when DRF's TokenAuthentication was used.

Remove bare except clauses

See merge request !617

A new check in flake8 complains about them.

Grayscale inaccessible albums

Closes #166

See merge request !614

Add a missing migration in the education app

See merge request !612

Optimize the activemembers admin

See merge request !609

Prevent setting automatic member payment fees to true without an IBAN.

Closes #452

See merge request !587

This commit makes the activemembers admin a lot faster by doing the
following two things:

1. Add `member` to `raw_id_fields` in the inline for committee
   memberships. Before the entire list of members was copied for every
   committee membership. This resulted in html pages of several
   megabytes.
2. Remove duplicate queries (for different ids) by adding
   `select_related` calls in the right places.

Fix profile save

See merge request !610

Use the User model for foreign keys.

See merge request !606

Resize profile images on upload

Closes #529

See merge request !608

Remove confusing 'cancel' button from registration info fields page

Closes #525

See merge request !603

Fix info fields in events API registrations

See merge request !601

Fix events table values in admin

See merge request !598

Fix context given to baseurl templatetag in events emails.py

See merge request !600

Update django-rest-framework to 3.7

See merge request !596

In particular, this resolves the template error wrt crispyforms
when deploying.

Translation is now with capital letters and the event export displays payment method correct.

See merge request !597

payment method correct.

Add part about committee promotion to styleguide

See merge request !584