title: include externals in subversion diff
body: <p>I have setup my project in SVN to use an external library.
  When I want to push some modifications to the live server I do a diff between versions and copy only the changed files. 
  My problem is that the diff does not check the external modifications also, it just returns the project modifications.</p>
  
  <p>What is your strategy to deploy modifications for projects with external code.</p>