Webpack all the things! Fixes #2135

This significantly speeds up loading of the application; in an average of 3 tests, v1.6
loaded in 11.5s in the runtime on a Mac, whilst the webpacked version of the code
loaded in 5.53s.

web/pgadmin/static/js/selection/clipboard.js

@@ -50,7 +50,6 @@ define(['sources/gettext', 'alertify'], function (gettext, alertify) {
          * called for each copy operation performed on any input/textarea from
          * this document.
          */
-        document.removeEventListener('copy', arguments.callee);
 
         var clipboardData = e.clipboardData || window.clipboardData;
 

web/pgadmin/static/js/selection/copy_data.js

@@ -7,7 +7,7 @@ define([
 ],
 function ($, _, clipboard, RangeSelectionHelper, rangeBoundaryNavigator) {
   var copyData = function () {
-    var self = this;
+    var self = this || window;
 
     var grid = self.slickgrid;
     var columnDefinitions = grid.getColumns();