chore(*): minor license changes and code cleanup

Author: onlyexeption

LICENSE

@@ -2,15 +2,15 @@ This is a commercial product, requiring a valid paid-for license for commercial
 This product is free to use for non-commercial educational use for students in K through 12 grades
 or University programs, and for educators to use in a classroom setting as examples / tools in their curriculum.
 
-This repository includes files originally copied from https://github.com/zloirock/core-js
-under setImmediate.ts. The original versions of the files are MIT licensed. See the file headers for details.
-
 In order for us to verify your eligibility for free usage, please register for trial at
 https://Infragistics.com/Angular and open a support ticket with a request for free license.
 
 To acquire a license for commercial usage, please register for trial at https://Infragistics.com/Angular
 and refer to the purchasing options in the pricing section on the product page.
 
+This repository includes code originally copied from https://github.com/zloirock/core-js
+in the projects/igniteui-angular/src/lib/core/setImmediate.ts file. The original version of the code is MIT licensed. See the file header for details.
+
 © Copyright 2020 INFRAGISTICS. All Rights Reserved.
 The Infragistics Ultimate license & copyright applies to this distribution.
 For information on that license, please go to our website https://www.infragistics.com/legal/license.

projects/igniteui-angular/ng-package.json

@@ -7,7 +7,6 @@
   },
   "whitelistedNonPeerDependencies": [
       "@types/hammerjs",
-      "core-js-pure",
       "hammerjs",
       "jszip",
       "resize-observer-polyfill",

projects/igniteui-angular/ng-package.prod.json

@@ -9,7 +9,6 @@
   },
   "whitelistedNonPeerDependencies": [
       "@types/hammerjs",
-      "core-js-pure",
       "hammerjs",
       "jszip",
       "resize-observer-polyfill",

projects/igniteui-angular/schematics/utils/dependency-handler.ts

@@ -29,7 +29,6 @@ export const DEPENDENCIES_MAP: PackageEntry[] = [
         { name: 'resize-observer-polyfill', target: PackageTarget.REGULAR },
         { name: '@types/hammerjs', target: PackageTarget.DEV },
         { name: 'igniteui-trial-watermark', target: PackageTarget.NONE },
-        { name: 'core-js-pure', target: PackageTarget.NONE },
         { name: 'lodash.merge', target: PackageTarget.NONE },
         // peerDependencies
         { name: '@angular/forms', target: PackageTarget.NONE },

projects/igniteui-angular/src/lib/core/setImmediate.ts

@@ -36,10 +36,13 @@ const listener = function (event) {
     run(event.data);
 };
 
+if (!window.setImmediate) {
+    window.addEventListener('message', listener, false);
+}
+
 export function setImmediate(cb: any) {
     if (window.setImmediate) {
-        window.setImmediate(cb);
-        return;
+        return window.setImmediate(cb);
     }
 
     const args = [];
@@ -54,15 +57,13 @@ export function setImmediate(cb: any) {
     };
 
     window.postMessage(counter + '', windowLocation.protocol + '//' + windowLocation.host);
-    window.addEventListener('message', listener, false);
 
     return counter;
 }
 
 export function clearImmediate(id: any) {
     if (window.clearImmediate) {
-        window.clearImmediate(id);
-        return;
+        return window.clearImmediate(id);
     }
 
     delete queue[id];