Log Message:
devel/jj: import package

Jujutsu is a Git-compatible DVCS. It combines features from Git (data model,
speed), Mercurial (anonymous branching, simple CLI free from "the index",
revsets, powerful history-rewriting), and Pijul/Darcs (first-class conflicts),
with features not found in most of them (working-copy-as-a-commit, undo
functionality, automatic rebase, safe replication via rsync, Dropbox, or
distributed file system).

The command-line tool is called jj for now because it's easy to type and easy
to replace (rare in English). The project is called "Jujutsu" because it
matches "jj".