Add box2d-2.2.1.

BUG=none
R=sbc@chromium.org

Review URL: https://codereview.chromium.org/11946010

git-svn-id: http://naclports.googlecode.com/svn/trunk/src@659 7dad1e8b-422e-d2af-fbf5-8013b78bd812
Speed up process of finding the latest SDK.

The old code took ~8 minutes to figure out which SDK to
download.  The new code avoids using '*' in calls to gsutil
ls.

Also, remove the dependacy on cygtar to untar toolchain,
except on win32.  This allows local testing without relying
on native_client/tools (or any other DEPS).

BUG=https://code.google.com/p/naclports/issues/detail?id=62

Review URL: https://codereview.chromium.org/11958007

git-svn-id: http://naclports.googlecode.com/svn/trunk/src@660 7dad1e8b-422e-d2af-fbf5-8013b78bd812
Add box2d to the waterfall

BUG=none
TBR=sbc@chromium.org

Review URL: https://codereview.chromium.org/11967028

git-svn-id: http://naclports.googlecode.com/svn/trunk/src@661 7dad1e8b-422e-d2af-fbf5-8013b78bd812