pwa versioning experiment 1

snap.html

@@ -20,7 +20,7 @@
         <script src="src/threads.js?version=2021-10-22"></script>
         <script src="src/objects.js?version=2021-10-26"></script>
         <script src="src/scenes.js?version=2021-10-12"></script>
-        <script src="src/gui.js?version=2021-10-26"></script>
+        <script src="src/gui.js?version=2021-10-26-a"></script>
         <script src="src/paint.js?version=2021-07-05"></script>
         <script src="src/lists.js?version=2021-07-19"></script>
         <script src="src/byob.js?version=2021-10-25"></script>

src/gui.js

@@ -4704,7 +4704,7 @@ IDE_Morph.prototype.aboutSnap = function () {
         module, btn1, btn2, btn3, btn4, licenseBtn, translatorsBtn,
         world = this.world();
 
-    aboutTxt = 'Snap! 7 - dev -\nBuild Your Own Blocks\n\n'
+    aboutTxt = 'Snap! 7 - dev alpha 1 -\nBuild Your Own Blocks\n\n'
         + 'Copyright \u24B8 2008-2021 Jens M\u00F6nig and '
         + 'Brian Harvey\n'
         + 'jens@moenig.org, bh@cs.berkeley.edu\n\n'

sw.js

@@ -1,3 +1,5 @@
+var SnapVersion = '7-dev-alpha1'
+
 var cacheName = 'snap-pwa',
     filesToCache = [
         'snap.html',