QPA: Fix event dispatcher dependent operations in platform integration

999e5162ec3e86c9cb84c3ec95dfd0ba4b21277f breaks QPlatformIntegration
implementations that perform tasks in their constructor that rely on
the event dispatcher. For example creating a QSocketNotifier is not
possible anymore since the event dispatcher is created later on.

This is fixed by introducing an additional virtual in
QPlatformIntegration that gets called after createEventDispatcher().

Two broken platform plugins have been identified so far: eglfs is
creating socket notifiers to read events from input devices and xcb's
input context plugins may use dbus. Both are updated accordingly.

Task-number: QTBUG-33768
Change-Id: I5badb623958a52ab5314ff93dd7d60061f5df70a
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@digia.com>
Allow to use short names for Windows Registry root keys

Change-Id: I58b7681bb49e93b7577bc559d754c81d3c6f007b
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
iOS: Skip qtconnectivity and qtlocation modules

These modules don't build for iOS or don't have a backend yet
Also organizing the list a bit while we are it.

Change-Id: Ic72e897325c9478f66af8e8f879fe6342eb327dc
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@digia.com>