iOS: Build libs (including Qt itself) for both simulator and device

Conceptually a Qt for iOS SDK or source build should support building
for both simulator and device, based on the same qmake binary and Qt
libraries. Qt Creator or Xcode should then be able to use the same Qt
version while still building for a single target at a time. This
applies to user libraries as well, which shouldn't require switching
to a different Qt when changing target platform from simulator to
device.

We achieve this by using Qt's exclusive_build feature, where we build
for the two targets in parallel, and then teach Xcode how to choose
the right library dynamically at build time.

Change-Id: I06d60e120d986085fb8686ced98f22f7047c4f23
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>
xcb: Act on the _NET_ACTIVE_WINDOW event

It happens that we don't get a focus inn event for top level windows
when focus goes from a window mapped. But we do get a _NET_ACTIVE_WINDOW
event.

Task-number: QTBUG-34426
Change-Id: Id1d9eb708a968e0e8934e56dec19abe2dd203bc7
Reviewed-by: Gunnar Sletta <gunnar.sletta@digia.com>
xcb: Compilefix #ifdef glx code

Change-Id: I4204cab76b2621318dda909d24ceb2abab6e0ba3
Reviewed-by: Gunnar Sletta <gunnar.sletta@digia.com>
remove compiler warning

Change-Id: I40750320d21165333b195aca7564a6f4ee9d9eef
Reviewed-by: Gunnar Sletta <gunnar.sletta@digia.com>