wtv-setup + bgmusic

- wtv-setup pages thanks to https://github.com/JarHead4
- wtv-backgroundmusic support
- keyboard and text size settings support
- removed small midi music demo in favor of backgroundmusic system
- version v0.9.23

zefie_wtvp_minisrv/ServiceVault/wtv-setup/validate-screen-border.js

@@ -0,0 +1,15 @@
+if (request_headers.query) {
+    if (request_headers.query.shade) {
+        headers = `300 OK
+Location: wtv-setup:/screen
+wtv-visit: client:setscreenborder?${request_headers.query.shade}`;
+    } else {
+        var errpage = wtvshared.doErrorPage(400);
+        headers = errpage[0];
+        data = errpage[1];
+    }
+} else {
+    var errpage = wtvshared.doErrorPage(400);
+    headers = errpage[0];
+    data = errpage[1];
+}