WebUSB: Disconnect, connect, reset REPL (bbcmicrobit#284)

Author: microbit-sam

python-main.js

@@ -1455,6 +1455,11 @@ function web_editor(config) {
 
         p.finally(function() {
             console.log('Disconnection Complete');
+            document.dispatchEvent(new CustomEvent('webusb', { 'detail': {
+                'flash-type': 'webusb',
+                'event-type': 'info',
+                'message': 'disconnected'
+            }}));
         });
 
         return p;
@@ -1492,10 +1497,12 @@ function web_editor(config) {
         $("#flashing-overlay-container").css("display", "flex");
 
         if (usePartialFlashing) {
-            // Push binary to board
-            p = doDisconnect()
+            REPL = null;
+            $("#repl").empty();
+
+            p = window.dapwrapper.disconnectAsync()
                 .then(function() {
-                        return doConnect();
+                    return PartialFlashing.connectDapAsync();
                 })
                 .then(function() {
                     var output = generateFullHex("bytes");