v0.4rc1

• Add --continue, --skip and --abort to pull rebase! (aa74a48)
• Add --create-branch option for pull new / pull attach (57d0db6)
• Lots of improvements to usability: better output (ed2345a, 051d904),
  improve error handling (7112aa8, cdd09df, 1bad245) and several new sanity
  checks (58481d8, 3206559, bfa89d0, 7171757)