significant rewrite of the $location service

- don't update browser before and after eval instead
  - sync location properties before eval
  - sync location properties and update browser after eval
- added tests
- symplified the code
- removed $location.toString() because it was not idempotent and useless

This resolves the issue with issuing two $route.onHashChange calls
when the $location was updated with a hashPath that needs to be encoded

test/angular-mocks.js

@@ -77,6 +77,8 @@ function MockBrowser() {
         }
       }
     );
+
+    return listener;
   };