Make git-cl more accurately imitate git's editor selection process, and respect $VISUAL.

tests/basic.sh

 #!/bin/bash
 
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 set -e
 
 . ./test-lib.sh
 
@@ skipping 11 matching lines @@
 
   test_expect_success "git-cl upload wants a server" \
     "$GIT_CL upload 2>&1 | grep -q 'You must configure'"
 
   git config rietveld.server localhost:8080
 
   test_expect_success "git-cl status has no issue" \
     "$GIT_CL status | grep -q 'no issue'"
 
   # Prevent the editor from coming up when you upload.
-  export EDITOR=$(which true)
+  export GIT_EDITOR=$(which true)
 
   test_expect_success "upload succeeds (needs a server running on localhost)" \
     "$GIT_CL upload -m test master | grep -q 'Issue created'"
 
   test_expect_success "git-cl status now knows the issue" \
     "$GIT_CL status | grep -q 'Issue number'"
 
   # Push a description to this URL.
   URL=$($GIT_CL status | sed -ne '/Issue number/s/[^(]*(\(.*\))/\1/p')
   curl --cookie dev_appserver_login="test@example.com:False" \
@@ skipping 16 matching lines @@
   test_expect_success "upstream svn has our commit" \
       "svn log $REPO_URL 2>/dev/null | grep -q 'foo-quux'"
 )
 SUCCESS=$?
 
 cleanup
 
 if [ $SUCCESS == 0 ]; then
   echo PASS
 fi