Bitbucket import: PRs from forks
After !34 (merged), we'll still have to figure out what to do of Bitbucket PRs made from a fork. That should be the vast majority of them.
We do have the full information about the source repository, branch and even sha. What's lacking is
- retrieval from the Bitbucket fork
- where to store them: we can't assume the fork owner is a user already
Could be for the 0.6 stable branch, but if that takes too much changes, we could reassing to 0.7.0