git cl was using system git cl.
- replace git cl status with GIT_CL_STATUS var
- add tested depot_tools to tip of PATH.

R=maruel@chromium.org
BUG=

Review URL: https://chromiumcodereview.appspot.com/20889002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@214021 0039d316-1c4b-4281-b951-d872f2087c98