[#1710] some simplification on Groups memoization. No need for all that

special handling of Header Party, just have it's own controller and do
specific-handling. Also, removing MenuCtrl & StatsCtrl - they weren't
used TMK, I think twas a vestige of mobile. @paglias give that a gander

public/js/controllers/headerCtrl.js

@@ -0,0 +1,10 @@
+"use strict";
+
+habitrpg.controller("HeaderCtrl", ['$scope', 'Groups', 'User',
+  function($scope, Groups, User) {
+    $scope.party = Groups.party();
+    $scope.partyMinusSelf = _.filter($scope.party, function(member){
+      return member._id !== User.user._id;
+    });
+  }
+]);