repo 1.6.8

1. d63bbf4 Work around 'ControlPath too long' on Mac OS X by Shawn O. Pearce · Tue Apr 21 08:05:27 2009 -0700
2. fb23161 Automatically use SSH control master support during sync by Shawn O. Pearce · Fri Apr 10 18:53:46 2009 -0700
3. ad3193a Fix `repo --trace` to show ref and config loads by Shawn O. Pearce · Sat Apr 18 09:54:51 2009 -0700
4. cf31fe9 Initial Contribution by The Android Open Source Project · Tue Oct 21 07:00:00 2008 -0700 v1.0