Move git-cl into depot_tools....

git_cl/README.testing

+Most of the tests require a local Rietveld server.
+
+To set this up:
+Method 1: Let the presubmit script do the work for you.
+   $ git cl presubmit
+
+Method 2: Manual.
+1) Check out a copy of Rietveld:
+     $ svn checkout http://rietveld.googlecode.com/svn/trunk/ rietveld
+   (Use git-svn if you must, but man is it slow.)
+2) Get the Google App Engine SDK:
+   http://code.google.com/appengine/downloads.html
+3) To run Rietveld you will need Django 1.0, which is not included
+   with the App Engine SDK.  Go to http://www.djangoproject.com/download ,
+   download a Django from the 1.0 series (it's in the sidebar on the right),
+   untar it, then
+     $ export PYTHONPATH=`pwd`/Django-1.0.4
+4) Run Rietveld:
+     $ /path/to/appengine/sdk/dev_appserver.py /path/to/rietveld
+   (If using one of the App Engine launchers, be sure to use port 8080
+   for this project.)
+
+And then, finally, run the tests.