Improve DataGrid View extension for webpack

[Gemorroj]

Need to change the scope of variables in module DataGrid View.
For example, "datagrid-bufferview.js", code:

Code:

var bufferview = $.extend({}, $.fn.datagrid.defaults.view, {

But in webpack, "var" - is local variable.
Change

Code:

var bufferview

to

Code:

window.bufferview

allow use this extension in webpack.

[fengdie]

in datagrid-bufferview.js

Code:

var bufferview = $.extend({}, $.fn.datagrid.defaults.view, {
......
module.exports = bufferview

other file use

Code:

let bufferview = require('easyui/extensions/datagrid/datagrid-bufferview.js')