Handle subscription of messages in the webapp.

Messages larger than a threshold are split and reassembled due to the
size limit in webrtc. Threshold may have to be adjusted somewhere between
64KiB and 256KiB.

This also includes a basic handler for a ping message and a more
advanced image handler.

Change-Id: If66acfb1bb84e9d3ff686994a94b1480cb70b2aa
diff --git a/y2020/www/main.ts b/y2020/www/main.ts
new file mode 100644
index 0000000..7831713
--- /dev/null
+++ b/y2020/www/main.ts
@@ -0,0 +1,11 @@
+import {Connection} from 'aos/network/www/proxy';
+
+import {ImageHandler} from './image_handler';
+
+const conn = new Connection();
+
+conn.connect();
+
+const iHandler = new ImageHandler();
+
+conn.addHandler(iHandler.getId(), (data) => iHandler.handleImage(data));