title: What does it mean when Git says 'rewrite' or 'rename' in a commit message?
body: <p>Running a <code>git commit</code> leads to the following output:</p>
  
  <pre><code>[manu@host] git: git commit -a -m "StreamIt instrumentation"
  [master 263410f] StreamIt instrumentation
  62 files changed, 6117 insertions(+), 5748 deletions(-)
  rewrite Code/ALCHEMY/streamit-src-2.1.1/src/at/dms/kjc/cluster/ClusterBackend.java (91%)
  rewrite Code/ALCHEMY/streamit-src-2.1.1/src/at/dms/kjc/cluster/ClusterCodeGenerator.java (95%)
  rewrite Code/ALCHEMY/streamit-src-2.1.1/src/at/dms/kjc/cluster/code/FlatIRToCluster.java (94%)
  rewrite Code/ALCHEMY/streamit-src-2.1.1/src/at/dms/kjc/common/ToCCommon.java (92%)
  rewrite Code/ALCHEMY/streamit-src-2.1.1/src/at/dms/kjc/flatgraph/ScheduledStaticStreamGraph.java (93%)
  rename Code/ALCHEMY/streamit-src-2.1.1/src/at/dms/kjc/sir/lowering/fission/{StatelessDuplicate.java =&gt; HorizontalFission.java} (98%)
  rewrite Code/ALCHEMY/streamit-src-2.1.1/src/at/dms/kjc/sir/lowering/partition/dynamicprog/DynamicProgPartitioner.java (93%)
  </code></pre>
  
  <ul>
  <li>What does git mean when it reports a file as 'rewrite'?  </li>
  <li>What is the meaning of the associated percentage?</li>
  <li>Why is a percentage only associated with these lines among the 62 changed in this commit?</li>
  </ul>