Don't translate input

When `send-encoding` is `utf-8`, hterm translate input from the
clipboard from UTF-16 to UTF-8, even when the input is indeed UTF-8.
This translation messes up all non ASCII input.

resources/gotty.js

@@ -15,6 +15,8 @@
 
             term = new hterm.Terminal();
 
+            term.getPrefs().set("send-encoding", "raw");
+
             term.onTerminalReady = function() {
                 var io = term.io.push();