Adding Mitogen plugin and strategy.

plugins/mitogen-0.3.44/tests/testmods/simple_pkg/a.py

@@ -0,0 +1,5 @@
+import testmods.simple_pkg.b
+
+
+def subtract_one_add_two(n):
+    return testmods.simple_pkg.b.subtract_one(n) + 2