Add unretweet support

Closes #103

See merge request !284

updated german translation

See merge request !269

Update Russian translation

See merge request pleroma/pleroma-fe!270

Improve user settings ui

See merge request !273

Hebrew Translation of "placeholder"

See merge request !278

Feature/locked accounts

See merge request !274

messages: rename content warning to subject

See merge request !280

Translate username input placeholder

See merge request !275

Add French translations for the new user settings

See merge request !271

Hebrew Translation

See merge request pleroma/pleroma-fe!277