Xpra: Ticket #2419: show shadow mouse position in html5 client

Same as was done for the python client using the mouse.show feature: show the pointer moving.

Sun, 22 Sep 2019 06:57:10 GMT - Antoine Martin: status changed; resolution set

Done in r23881.

Only difference with the python client is that we don't hide it after a few seconds when it stops moving.

Sat, 23 Jan 2021 05:50:47 GMT - migration script:

this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/2419