title: Getting NAnt to check for changed files in SVN
body: <p>In the interests of trying to speed up my NAnt/CruiseControl.Net/Ivy continuous build process, I was hoping to get NAnt to check if my codebase has changed on my local PC after performing a NAnt-based  update, and then if the code <em>has</em> changed, then kick off the process to re-build that project and possibly raise a flag to build all subsequent components, irrespective of their change status.</p>
  
  <p>Reason being, my build process is currently taking well over 12 minutes to complete a lot of work, and I'm thinking that I can get this time down by not building code that isn't going to change, as well as keep the devs in the office happier also.</p>
  
  <p>We have investigated removing some of the projects from the build order, but they are all required in case of any change further up the build tree order.</p>