Revert "Call stopListening on module stop"

This reverts commit b8075a2fef4d366d19ba986cd201eb904497d69f.

per comments from @disruptek about this being breaking from him.
https://github.com/marionettejs/backbone.marionette/pull/1022#issuecomment-39014298

This behavior will be placed into the 2.x release as part of the larger module rework to introduce a more fine grained concept of a lifecycle and a "Stop" much like  https://github.com/marionettejs/backbone.marionette/pull/801