[PATCH xserver 0/5] Fix ephyr events. Add ephyr/glamor resize

[Keith Packard]

Here's a short subset of the 'epoll' branch which changes the event
processing in ephyr so that any events left queued in xcb by server
execution will get processed before the server blocks.

In doing this work, I discovered that ephyr didn't handle window
resize when using glamor.

And, configure event processing would end up calling configure_window,
which caused some entertaining loops when you had multiple configure
notify events queued before processing them.

Finally, configure notify event processing wasn't skipping multiple
configure events, which made the above case happen quite often.

The first patch is the existing restructuring of block/wakeup handlers
which is required before the rest of this series works.