[product/ERP5Type] Introduce Log.py for compatibility

Without it, it is not possible to upgrade instances since:
nexedi/erp5@48c45fbd

product/ERP5Type/Log.py

+##############################################################################
+#
+# Copyright (c) 2007 Nexedi SA and Contributors. All Rights Reserved.
+#                    Yoshinori Okuji <yo@nexedi.com>
+#
+# WARNING: This program as such is intended to be used by professional
+# programmers who take the whole responsability of assessing all potential
+# consequences resulting from its eventual inadequacies and bugs
+# End users who are looking for a ready-to-use solution with commercial
+# garantees and support are strongly adviced to contract a Free Software
+# Service Company
+#
+# 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.
+#
+##############################################################################
+
+from Products.ERP5Type.Utils import deprecated
+from zLOG import (
+  LOG,
+  INFO
+)
+
+marker_ = []
+
+@deprecated
+def log(description, content=marker_, level=INFO):
+    """Deprecated method
+
+    Use erp5.componement.Log instead.
+    
+    Kept for compatbility to allow instance upgrade.
+    """
+    if content is marker_: # allow for content only while keeping interface
+        description, content = content, description
+    LOG(description, level, content)

product/ERP5Type/__init__.py

@@ -179,6 +179,7 @@ ModuleSecurityInfo('Products.ERP5Type.Message').declarePublic('translateString')
 allow_module('Products.ERP5Type.Error')
 allow_module('Products.ERP5Type.Errors')
 allow_module('Products.ERP5Type.JSONEncoder')
+allow_module('Products.ERP5Type.Log')
 allow_module('Products.ERP5Type.ImmediateReindexContextManager')
 ModuleSecurityInfo('Products.ERP5Type.JSON').declarePublic('dumps', 'loads')
 ModuleSecurityInfo('Products.ERP5Type.Constraint').declarePublic('PropertyTypeValidity')