Merge ast-branch to head

This change implements a new bytecode compiler, based on a
transformation of the parse tree to an abstract syntax defined in
Parser/Python.asdl.

The compiler implementation is not complete, but it is in stable
enough shape to run the entire test suite excepting two disabled
tests.

Lib/test/test_repr.py

@@ -123,7 +123,7 @@ class ReprTests(unittest.TestCase):
 
     def test_lambda(self):
         self.failUnless(repr(lambda x: x).startswith(
-            "<function <lambda"))
+            "<function lambda"))
         # XXX anonymous functions?  see func_repr
 
     def test_builtin_function(self):