Handle local renamed but uncommitted files (git mv).

[kanet77]

Accept git status output lines beginning with R in addition to the already accepted prefixes (A, M, D, UU, or ??).

I'm not convinced that the git status after popping is correct. The status is: local_dir.should have_git_status({:deleted=>["lib/codes.rb"], :added=>["lib/codes2.rb"]}) I would expect: local_dir.should have_git_status({:renamed=>["lib/codes2.rb"]})