Fixed `git this` when run from a subdir.

`git this` now captures the entire work tree. `git these` captures the cwd
only.
Added 'bsummary' (Branch Summary) command.

Turns out I use --oneline a lot.
Merge pull request #4 from ojacobson/bsummary

Added 'bsummary' (Branch Summary) command.
Use common-ancestor notation for bdiff

Diff "along" the branch is more useful than absolute state diff between
upstream and branch head.
Whitespace normalization.
Merge pull request #6 from ojacobson/indentation

Whitespace normalization.
Merge pull request #5 from ojacobson/bdiff-dots

Use common-ancestor notation for bdiff
Merge pull request #7 from ojacobson/this-path

Fixed `git this` when run from a subdir.