title: GoogleAuthUtil vs AcountManager for getting token
body: <p>Need your advice.<p>
  Can't understand clearly - when <a href="http://developer.android.com/reference/android/accounts/AccountManager.html#getAuthToken%28android.accounts.Account,%20java.lang.String,%20android.os.Bundle,%20android.app.Activity,%20android.accounts.AccountManagerCallback%3Candroid.os.Bundle%3E,%20android.os.Handler%29" rel="nofollow">AccountManager.getAuthToken ()</a> should be used and when <a href="http://developer.android.com/reference/com/google/android/gms/auth/GoogleAuthUtil.html#getToken%28android.content.Context,%20java.lang.String,%20java.lang.String%29" rel="nofollow">GoogleAuthUtil.getToken()</a>. Please help make demarcation. <br>I personnaly need to authentificate for AppEngine access from an Android app.
  <p>Thanks</p>