set up testing environment for larger code base

snap.html

@@ -8,15 +8,19 @@
         <script type="text/javascript" src="src/symbols.js?version=2020-02-10"></script>
         <script type="text/javascript" src="src/widgets.js?version=2020-01-03"></script>
         <script type="text/javascript" src="src/blocks.js?version=2020-02-11"></script>
-<!--
+
         <script type="text/javascript" src="src/threads.js?version=2019-12-19"></script>
         <script type="text/javascript" src="src/objects.js?version=2020-01-28"></script>
         <script type="text/javascript" src="src/gui.js?version=2020-01-28"></script>
+<!--
         <script type="text/javascript" src="src/paint.js?version=2019-06-27"></script>
+//-->
         <script type="text/javascript" src="src/lists.js?version=2019-12-08"></script>
         <script type="text/javascript" src="src/byob.js?version=2020-01-03"></script>
         <script type="text/javascript" src="src/tables.js?version=2020-01-03"></script>
+<!--
         <script type="text/javascript" src="src/sketch.js?version=2019-10-09"></script>
+//-->
         <script type="text/javascript" src="src/video.js?version=2019-06-27"></script>
         <script type="text/javascript" src="src/maps.js?version=2019-10-28"></script>
         <script type="text/javascript" src="src/xml.js?version=2019-06-27"></script>
@@ -26,7 +30,6 @@
         <script type="text/javascript" src="src/api.js?version=2019-12-18"></script>
         <script type="text/javascript" src="src/sha512.js?version=2019-06-27"></script>
         <script type="text/javascript" src="src/FileSaver.min.js?version=2019-06-27"></script>
-//-->
         <script type="text/javascript">
             var world;
             window.onload = function () {

src/tables.js

@@ -70,7 +70,7 @@ SpriteMorph, Context, Costume, ArgMorph, BlockEditorMorph, SymbolMorph, List,
 SyntaxElementMorph, MenuMorph, SpriteBubbleMorph, SpeechBubbleMorph, Sound,
 CellMorph, ListWatcherMorph, isNil, BoxMorph, Variable, isSnapObject*/
 
-modules.tables = '2020-January-03';
+modules.tables = '2020-February-20';
 
 var Table;
 var TableCellMorph;
@@ -274,7 +274,7 @@ TableCellMorph.uber = Morph.prototype;
 
 // TableCellMorph global setting:
 
-TableCellMorph.prototype.listSymbol = ArgMorph.prototype.listIcon();
+TableCellMorph.prototype.listSymbol = null; // +++ disabled while working on rendering +++ ArgMorph.prototype.listIcon();
 
 // TableCellMorph instance creation: