title: git diff filtered by file name
body: <p>I would like the results of <code>git diff</code> to be filtered by the file name.</p>
  
  <p>In particular, I want a diff for all of the files named "AssemblyInfo.cs", but located anywhere within the git repository.</p>
  
  <p>I am using git on Cygwin, if that makes a difference.</p>