Reduce circular dependencies caused by importing from indexes, the location of the validation models, and the location of areaKeys (close #6237)

modules/util/detect.js

@@ -1,6 +1,6 @@
 import { currentLocale, setTextDirection } from './locale';
 import { dataLocales } from '../../data/index';
-import { utilStringQs } from './index';
+import { utilStringQs } from './util';
 
 var detected;
 

modules/util/keybinding.js

@@ -3,7 +3,7 @@ import {
     select as d3_select
 } from 'd3-selection';
 
-import { utilArrayUniq } from '../util/index';
+import { utilArrayUniq } from './array';
 
 
 export function utilKeybinding(namespace) {

modules/util/tooltip.js

@@ -1,5 +1,5 @@
 import { select as d3_select } from 'd3-selection';
-import { utilFunctor } from './index';
+import { utilFunctor } from './util';
 
 var _tooltipID = 0;