title: git rebase -- unexpected mismatch of my hashes
body: <p>1) why wasn't i given an opportunity to stage pieces of my commits so i can tease them into distinct commits before merging with <em>team</em>?
  2) why doesn't the hash before the rebase equal to the hash after the rebase? I see no messages indicating there was a squashed whitespace or something.</p>
  
  <pre><code>GIT [work]  git log --oneline -n10
  7784ea8 dataloader populates with relatively sane data for masteritem and event; some component changes
  1d9b3fe masterlist, promote draft, various commands, display tweaks on all components
  76bea59 display strings
  ...
  GIT [work]  git rebase -i team
  </code></pre>
  
  <p>edit first commit, squash next two commits</p>
  
  <pre><code>Stopped at 76bea59... display strings
  You can amend the commit now, with
  
          git commit --amend
  
  Once you are satisfied with your changes, run
  
          git rebase --continue
  
  PS [55] git status
  # Not currently on any branch.
  nothing to commit (working directory clean)
  PS [56] git rebase --continue
  [detached HEAD e373567] display strings
   49 files changed, 917 insertions(+), 460 deletions(-)
   delete mode 100644 source/...
   delete mode 100644 source/...
   delete mode 100644 source/...
   ...
  Successfully rebased and updated refs/heads/work.
  GIT [work]  git log --oneline -n10
  e373567 display strings
  bddc2fe unit test for object attrs, verify repeating in framework
  548e1e9 sync with cvs; fixed test case compile error
  </code></pre>