shiny/driver/x11driver: send config events.

Also fix support for the ICCCM WM_TAKE_FOCUS protocol:
https://tronche.com/gui/x/icccm/sec-4.html#s-4.1.7

Change-Id: Ic41fa71d6f2f78b82d9b7a8a0459561a99b4304f
Reviewed-on: https://go-review.googlesource.com/13210
Reviewed-by: Rob Pike <r@golang.org>
3 files changed