#1855 MediaProxy cache invalidation via Admin API

See merge request pleroma/pleroma!2648

README: Add some troubleshooting info for compilation issues.

See merge request pleroma/pleroma!2660

[#1873] :offset pagination param support, hashtags pagination

Closes #1873

See merge request pleroma/pleroma!2659

User: update_follower_count refactor.

See merge request pleroma/pleroma!2649

[#1873] Fixes missing :offset pagination param support. Added pagination support for hashtags search.

Change references from "deleted_urls" to "banned_urls" as nothing is handled via media deletions anymore; all actions are manual operations by an admin to ban the url

Moving custom ecto types in context folders

See merge request pleroma/pleroma!2652

Remove `poll` from `notification_type` OpenAPI spec

Closes #1867

See merge request pleroma/pleroma!2657

User: Add raw_bio, storing unformatted bio

See merge request pleroma/pleroma!2326

Update elixir image used for OTP releases

See merge request pleroma/pleroma!2654

This is necessary since we bumped required version of elixir to 1.9.

The dlsym bug should be gone by now.

Chunk the notification type backfill migration

See merge request pleroma/pleroma!2653

Long-term we want that migration to be done entirely in SQL,
but for now this is a hotfix to not cause OOMs on large databases.

This is using a homegrown version of `Repo.stream`, it's worse in
terms of performance than the upstream since it doesn't use the same
prepared query for chunk queries, but unlike the upstream it supports
preloads.

Resolve "/api/v1/conversations returns the wrong `last_status`"

Closes #1866

See merge request pleroma/pleroma!2647

Upgrade to Elixir 1.9

See merge request pleroma/pleroma!2651

Mogrify args in adminFE

Closes #1787

See merge request pleroma/pleroma!2616