ws_client.disconnect() blocks until the close handshake completes
(observed ~10s when the server doesn't ack promptly), and was being
called straight from the Connect/Disconnect button's click handler -
joining that wait on the GUI thread, so the click appeared to do
nothing until the timeout passed. Run it off a throwaway thread
instead; on_ws_connect_changed() already flips the button once the
disconnect actually finishes.
jens
127dd9da51