add new git-deps for automatic dependency calculation
git-deps: refactor into new DependencyDetector class
git-deps: add logging and recursion
git-deps: debug to STDOUT
git-deps: add --context-lines
git-deps: add listener classes
git-deps: tweaks to improve debugging
git-deps: don't crash on commits which only add files
git-deps: invoke git blame in more reliable manner
git-deps: add first line of commits to debug
git-deps: improve --help for --context-lines
git-deps: --help: put short options first
git-deps: use new-style classes
git-deps: output dependencies as soon as they're found
git-deps: ignore KeyboardInterrupt
git-deps: allow multiple dependents on ARGV, and fix usage string
git-deps: fix abort()
git-deps: add --exclude-commits
git-deps: improve help text
git-deps: fix error message