Xpra: Ticket #875: make OR windows use xshm

This was disabled a while back because OR windows tend to be small and short lived. But some applications may well use them for fullscreen video, which would slow us down considerably, especially at high res. (at least Firefox and Chrome don't use OR with youtube videos playing fullscreen, but maybe other video players do?)

Fri, 29 May 2015 04:39:31 GMT - Antoine Martin: status, description changed; resolution set

Done in r9547.

(this ticket is mostly here as a reminder of this tiny but significant change - will re-open if this causes problems)

Sat, 23 Jan 2021 05:08:32 GMT - migration script:

this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/875