2to3: Apply the 'exec' fixer

2to3-fixers.txt

 lib2to3.fixes.fix_basestring
 lib2to3.fixes.fix_dict
-lib2to3.fixes.fix_exec
-lib2to3.fixes.fix_execfile
 lib2to3.fixes.fix_funcattrs
 lib2to3.fixes.fix_future
 lib2to3.fixes.fix_has_key

Cython/Tempita/_tempita.py

@@ -315,7 +315,7 @@ class Template(object):
     def _exec(self, code, ns, pos):
         __traceback_hide__ = True
         try:
-            exec code in self.default_namespace, ns
+            exec(code, self.default_namespace, ns)
         except:
             exc_info = sys.exc_info()
             e = exc_info[1]