add stubs for pluggable implementations

implementation/__init__.py

@@ -0,0 +1,13 @@
+import os
+import glob
+import abc
+
+modules = glob.glob(os.path.dirname(__file__) + '/*.py')
+__all__ = [os.path.basename(f)[:-3] for f in modules]
+
+class ibuddy:
+    __metaclass__ = abc.ABCMeta
+
+    @abc.abstractmethod
+    def test(self):
+        return