Checkpoint.  218 tests are okay; 53 are failing.  Done so far:
- all classes are new-style (but ripping out classobject.[ch] isn't done)
- int/int -> float
- all exceptions must derive from BaseException
- absolute import
- 'as' and 'with' are keywords
diff --git a/Include/pythonrun.h b/Include/pythonrun.h
index 1ecb3d7..52623ba 100644
--- a/Include/pythonrun.h
+++ b/Include/pythonrun.h
@@ -7,9 +7,8 @@
 extern "C" {
 #endif
 
-#define PyCF_MASK (CO_FUTURE_DIVISION | CO_FUTURE_ABSIMPORT | \
-                   CO_FUTURE_WITH_STATEMENT)
-#define PyCF_MASK_OBSOLETE (CO_NESTED)
+#define PyCF_MASK 0
+#define PyCF_MASK_OBSOLETE 0
 #define PyCF_SOURCE_IS_UTF8  0x0100
 #define PyCF_DONT_IMPLY_DEDENT 0x0200
 #define PyCF_ONLY_AST 0x0400