Migrate to TS 4.1

Tools/Gulp/package.json

@@ -12,8 +12,5 @@
         "install": "cd ../../ && npm install && cd Playground/ && npm install && cd ../Viewer && npm install && cd ../Tools/Gulp/",
         "build": "gulp --max-old-space-size=8192 --tsLintFix",
         "start": "gulp run --max-old-space-size=8192"
-    },
-    "dependencies": {
-        "typescript": "^3.3.3333"
     }
 }

gui/src/2D/controls/inputText.ts

@@ -758,7 +758,7 @@ export class InputText extends Control implements IFocusableControl {
         this._isTextHighlightOn = false;
         //when write permission to clipbaord data is denied
         try {
-            ev.clipboardData.setData("text/plain", this._highlightedText);
+            ev.clipboardData && ev.clipboardData.setData("text/plain", this._highlightedText);
         }
         catch { } //pass
         this._host.clipboardData = this._highlightedText;
@@ -773,7 +773,7 @@ export class InputText extends Control implements IFocusableControl {
         this._cursorOffset = this.text.length - this._startHighlightIndex;
         //when write permission to clipbaord data is denied
         try {
-            ev.clipboardData.setData("text/plain", this._highlightedText);
+            ev.clipboardData && ev.clipboardData.setData("text/plain", this._highlightedText);
         }
         catch { } //pass