Add stub port of os.jam.

[SVN r64444]

v2/build/project.py

@@ -1003,11 +1003,14 @@ attribute is allowed only for top-level 'project' invocations""")
     def import_(self, name, names_to_import=None, local_names=None):
 
         name = name[0]
+        py_name = name
+        if py_name == "os":
+            py_name = "os_j"
         jamfile_module = self.registry.current().project_module()
         attributes = self.registry.attributes(jamfile_module)
         location = attributes.get("location")
 
-        m = self.registry.load_module(name, [location])
+        m = self.registry.load_module(py_name, [location])
 
         for f in m.__dict__:
             v = m.__dict__[f]

v2/util/os_j.py

@@ -0,0 +1,16 @@
+# Status: stub, just enough to make tests work.
+#
+# Named os_j to avoid conflicts with standard 'os'. See
+# project.py:import for special-casing.
+#
+# Copyright 2001, 2002, 2003, 2005 Dave Abrahams
+# Copyright 2006 Rene Rivera
+# Copyright 2003, 2005 Vladimir Prus
+# Distributed under the Boost Software License, Version 1.0.
+# (See accompanying file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
+
+
+import os
+
+def name():
+    return os.name