use "event.key" to detect (+) and (-) keystrokes across browsers

snap.html

@@ -4,7 +4,7 @@
         <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
         <title>Snap! Build Your Own Blocks 5 - Beta -</title>
         <link rel="shortcut icon" href="src/favicon.ico">
-        <script type="text/javascript" src="src/morphic.js?version=2019-02-07"></script>
+        <script type="text/javascript" src="src/morphic.js?version=2019-05-21"></script>
         <script type="text/javascript" src="src/widgets.js?version=2019-04-05"></script>
         <script type="text/javascript" src="src/blocks.js?version=2019-05-20"></script>
         <script type="text/javascript" src="src/threads.js?version=2019-05-15"></script>

src/morphic.js

@@ -1162,7 +1162,7 @@
 
 /*global window, HTMLCanvasElement, FileReader, Audio, FileList, Map*/
 
-var morphicVersion = '2019-February-07';
+var morphicVersion = '2019-May-21';
 var modules = {}; // keep track of additional loaded modules
 var useBlurredShadows = getBlurredShadowSupport(); // check for Chrome-bug
 
@@ -5827,6 +5827,8 @@ CursorMorph.prototype.inspectKeyEvent = function (event) {
             event.charCode.toString() +
             '\nkeyCode: ' +
             event.keyCode.toString() +
+            '\nkey: ' +
+            event.key.toString() +
             '\nshiftKey: ' +
             event.shiftKey.toString() +
             '\naltKey: ' +

src/objects.js

@@ -7667,16 +7667,10 @@ StageMorph.prototype.processKeyEvent = function (event, action) {
     case 40:
         keyName = 'down arrow';
         break;
-    case 171: // Firefox
-    case 187: // Chrome, Safari
-        keyName = '+';
-        break;
-    case 173: // Firefox
-    case 189: // Chrome, Safari
-        keyName = '-';
-        break;
     default:
-        keyName = String.fromCharCode(event.keyCode || event.charCode);
+        keyName = event.key || String.fromCharCode(
+            event.keyCode || event.charCode
+        );
         if (event.ctrlKey || event.metaKey) {
             keyName = 'ctrl ' + (event.shiftKey ? 'shift ' : '') + keyName;
         }