Fix for user defined modules not overriding modules from core.

This fix takes into account that powershell modules are somewhat
different than regular modules and have to be kept separate.

lib/ansible/plugins/connection/__init__.py

@@ -57,6 +57,10 @@ class ConnectionBase(with_metaclass(ABCMeta, object)):
 
     has_pipelining = False
     become_methods = C.BECOME_METHODS
+    # When running over this connection type, prefer modules written in a certain language
+    # as discovered by the specified file extension.  An empty string as the
+    # language means any language.
+    module_implementation_preferences = ('',)
 
     def __init__(self, play_context, new_stdin, *args, **kwargs):
         # All these hasattrs allow subclasses to override these parameters