MastoAPI: Persist frontend timelines and settings.

Closes #113

See merge request pleroma/pleroma!98

This should be the data the user is allowed to see later, but this
will stop accidental private message leaks.

webfinger: handle situations where the well-known endpoint returns HTML

See merge request pleroma/pleroma!94

Follow import: allow URI in addition to screen_name.

See merge request pleroma/pleroma!96

It doesn't work correctly.

Fix failure to serve media from custom upload path

See merge request pleroma/pleroma!95

Bring mastofe up to date

See merge request pleroma/pleroma!93

Commit https://git.pleroma.social/tyge/mastofe/commit/5edce2030238293463c041537da4aaeea5cb3875

summary:

```
*   5edce203 - (4 minutes ago) Merge branch 'master' of github.com:tootsuite/mastodon - Morgan Bazalgette (HEAD -> master, origin/master, origin/HEAD)
|\
| * 2c51bc0c - (4 hours ago)  Add missing rejection handling for Promises (#7008) - unarist (upstream/master)
| * e7a17167 - (5 hours ago) Implement the ability for an Administrator or Moderator to remove an account avatar (#6998) - Emelia Smith
| * 4fd71acc - (5 hours ago) Fix issues with sending direct messages from user profile (#6999) - Emelia Smith
| * 3f51c6ef - (5 hours ago) Weblate translations (2018-04-02) (#7007) - Yamagishi Kazutoshi
| * b04f73ce - (6 hours ago) Russian language updated (#7005) - Evgeny Petrov
| * 24611d8d - (6 hours ago) i18n: update zh-HK translation (#7004) - luzi82
| * f890d2a7 - (16 hours ago) Support all ActivityPub actor types (#6997) - Eugen Rochko
| * 33513753 - (16 hours ago) Fix unpermitted parameters warning when generating pagination URLs (#6995) - Eugen Rochko
| * 123a343d - (19 hours ago) [WIP] Enable custom emoji on account pages and in the sidebar (#6124) - David Underwood
| * f464f98f - (19 hours ago) Update Ruby to version 2.4.4 (#6964) - Yamagishi Kazutoshi
| * 6a895e1a - (20 hours ago) Fix: Prevent submission using same logic as submit button disabling. (#6993) - Emelia Smith
* | 011eda08 - (7 minutes ago) Properly cache requests using service workers - Morgan Bazalgette
* | 8dd77f17 - (5 hours ago) Fix build - Morgan Bazalgette
* | 99373236 - (19 hours ago) Add build status - Morgan Bazalgette
* | b448a3a5 - (19 hours ago) Update README - Morgan Bazalgette
* | 68fd7ee6 - (20 hours ago) Fix statuses embedded in like/boost notifs being white - Morgan Bazalgette
* | 7a9212df - (21 hours ago) Temporary workaround to only show related statuses - Morgan Bazalgette
* |   00bd10fa - (26 hours ago) Merge branch 'master' of github.com:tootsuite/mastodon - Morgan Bazalgette
|\ \
| |/
| * 993ce0e5 - (28 hours ago) improve zh-HK localization by referring zh-TW and zh-CN (#6988) - luzi82
* |   05832497 - (30 hours ago) Merge branch 'master' of github.com:tootsuite/mastodon - Morgan Bazalgette
 \ \
  |/
  * 929f58f1 - (32 hours ago) i18n: Update Polish translation (#6985) - Marcin Mikołajczak
```

masto api: run emojis through mediaproxy

Closes #107

See merge request pleroma/pleroma!92

fixes #107

update mastofe

See merge request !90

web endpoint: better document CORS stuff with nginx

See merge request pleroma/pleroma!82

mastodon search api: implement a reasonable hashtags stub

See merge request pleroma/pleroma!89

config: make the upload limit configurable

See merge request pleroma/pleroma!88