Follow up from #1670.
The changelog: log/xpra/trunk/src/html5
Lots of goodies in the latest chrome builds: Chrome 66 Beta: CSS Typed Object Model, Async Clipboard API, AudioWorklet:
(from The ImageBitmap rendering context for canvas) - not sure about zerocopy since this populates a canvas but worth a look
See also #1847: html5 native notifications api
We should also implement the same code as r19727: skip sending keyboard and mouse if the server doesn't handle those, see ticket:1838#comment:8.
Will follow up in #1979
this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/1788