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* Set "diff.renameLimit" to unlimited
  After this change, sourcezap always forwards "-l0" to "git diff"

* Replace utils/gitexec with utils/git/run
  After this change, we talk to git via utils/git/run

* Add utils/git/
  A dedicated directory for git-related scripts

* Remove "set -x"
  After this change, sourcezap emits less output

* Remove scripts
  Remove "utils/printok", "utils/printerr", "utils/git-rev"

* Add documentation
  Covers README.md and sourcezap.8