Add pylint to depot_tools.

third_party/pylint.py

+#!/usr/bin/env python
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free Software
+# Foundation; either version 2 of the License, or (at your option) any later
+# version.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details
+#
+# You should have received a copy of the GNU General Public License along with
+# this program; if not, write to the Free Software Foundation, Inc.,
+# 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+""" Copyright (c) 2002-2008 LOGILAB S.A. (Paris, FRANCE).
+http://www.logilab.fr/ -- mailto:contact@logilab.fr
+"""
+import sys
+from pylint import lint
+lint.Run(sys.argv[1:])