Make gcl and git-cl don't throw when a vim user does :cg

gcl.py

Index: gcl.py
diff --git a/gcl.py b/gcl.py
index 413e2bb6d361918276ff823db8d92a561e12b55f..f64f67221863c691754b415527ae7b82ab7e18d6 100755
--- a/gcl.py
+++ b/gcl.py
@@ -1119,8 +1119,12 @@ def CMDchange(args):
       if sys.platform == 'win32' and os.environ.get('TERM') == 'msys':
         # Msysgit requires the usage of 'env' to be present.
         cmd = 'env ' + cmd
-      # shell=True to allow the shell to handle all forms of quotes in $EDITOR.
-      subprocess.check_call(cmd, shell=True)
+      try:
+        # shell=True to allow the shell to handle all forms of quotes in
+        # $EDITOR.
+        subprocess.check_call(cmd, shell=True)
+      except subprocess.CalledProcessError, e:
+        ErrorExit('Editor returned %d' % e.returncode)
     result = gclient_utils.FileRead(filename, 'r')
   finally:
     os.remove(filename)