title: repo init a particular commit
body: <p>Im building the Cyanogenmod 9 (Android ICS) system for a Nexus S phone (samsung crespo).
  The problem is that if I do:</p>
  
  <pre><code>repo init -u git://github.com/CyanogenMod/android.git -b ics  
  </code></pre>
  
  <p>The repo inits to the latest commit of ICS, in which the manifest does not include some device/samsung/ projects I need (specifically <a href="https://github.com/CyanogenMod/android_device_samsung_crespo" rel="noreferrer">https://github.com/CyanogenMod/android_device_samsung_crespo</a>).</p>
  
  <p>How do I repo init to a particular commit?
  In my case I want the last commit using the google android-4.0.3_r1 branch.
  Is this one:</p>
  
  <ul>
  <li><a href="https://github.com/CyanogenMod/android/commit/5f5da775f570f2995c8ff2db98e6c8b40852911c" rel="noreferrer">https://github.com/CyanogenMod/android/commit/5f5da775f570f2995c8ff2db98e6c8b40852911c</a></li>
  </ul>
  
  <p>If I do</p>
  
  <blockquote>
    <p>repo init -u git://github.com/CyanogenMod/android.git -b commit-hash</p>
  </blockquote>
  
  <p>Does not  work, seems that repo init -b only support the HEAD of a branch.</p>
  
  <p>Thanks in Advance.</p>