Add warning message when a module is reset/replaced

- Add log to loader.js in case module with the same name is loaded again. The logProvider is not available at this point and after discussion on ng-europe we decided to use console.log.
- The result of the fix was tons of messages 
LOG: 'The module 'ng' already exists and has been redefined.'
because publishExternalAPI was called twice for EVERY test. Therefore  publishExternalAPI(angular); could be removed from testabilityPatch.js.

Fix for #6034 
Just another idea. In general I not really happy with with fix. This log looks a bit strange there. On ng-europe I heard about angular-hint that is designed just for such cases. Probably it would be better to handle this case with an additional rule for angular-hint.