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 
use $log here instead of window.console.log :<