Test for null-content activities.

See merge request !422

Add CORSPlug to make web-based OAuth easier.

See merge request !420

Pleroma.Web.MastodonAPI.StatusView: Content isn’t nullable

See merge request !421

Test for case-insensitive mastodon hashtag timelines.

See merge request !419

Fix hashtag search

See merge request !418

When we lowercase the search it will succesfully do a case insenstive
match. Now #Linux will match #linux and #LINUX whereas previously it
would only match the exact case.

Check for empty string in_reply_to ids.

Closes #355

See merge request !417

Pleroma.Web.TwitterAPI.ActivityView: Harden TwitterAPI against remnant of prismo

Closes #353

See merge request !415

AS2 page support (prismo)

See merge request !413

Ensure filters have a filter_id

See merge request !412

relay tests

See merge request !411

Bugfix/prismo.news article url

Closes #352

See merge request !410

Thanks prismo.news, I hate it

object cache deletion refactoring, part 2

See merge request !409

refactor object cache deletion

See merge request !408