Staging instance, all changes can be removed at any time

Darcs loader

We need a loader for Darcs repositories.

Given the peculiarities of the Darcs patch model, supporting it might entail changes in our data model (please add them as subtasks if needed).

Migrated from T273 (view on Phabricator)

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information