Increase the number of concurrent DNS lookups.

Modern websites use around 15 hosts on average so the limit of 5 DNS
looks meant that most non-trivial sites have to wait for at least one
unneeded round trip.

Task-number: QTBUG-30866
Change-Id: I584dd46c247e0413b2ed88dd66f111cff08ff987
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Refactor the handling of the navigator swipe down event

The navigator swipe down event is not mapped to a platform panel event any more.
Instead the NavigatorEventHandler is exposed through the QPlatformNativeInterface.

Change-Id: I6d29bba011849da5210f6f4d595e3c2e0c021449
Reviewed-by: Bernd Weimer <bweimer@blackberry.com>
Reviewed-by: Rafael Roquetto <rafael.roquetto@kdab.com>
[QNX] Don't deactivate windows focus

When the focus changes, screen sends a focus deactivated change for the focus window.
Depending on the order, this might deactivate the window focus completely. This
for example leads to problems with QComboBox.

Change-Id: Ia57f061a765c1f971d86d941b17f573ce9221ae1
Reviewed-by: Kevin Krammer <kevin.krammer@kdab.com>
Reviewed-by: Bernd Weimer <bweimer@blackberry.com>
Reviewed-by: Rafael Roquetto <rafael.roquetto@kdab.com>