Prevent change visibility of a repo in the UI when disallowed by billing plan

Fixes #486

- Extracts out the check plan logic and UI from the new repo page into its own directive (repo-count-checker)
- Adds the new directive to the repo settings panel
- Some additional UI improvements for the repo settings panel

static/js/services/user-service.js

@@ -126,6 +126,10 @@ function(ApiService, CookieService, $rootScope, Config) {
     return userResponse;
   };
 
+  userService.isUserNamespace = function(namespace) {
+    return namespace == userResponse.username;
+  };
+
   // Update the user in the root scope.
   userService.updateUserIn($rootScope);