Direct2D QPA: Speed up widget painting

By only starting/ending drawing once in the backing store, we can avoid
multiple start/ends and thus flushes of the direct2d device context. This
can potentially be much faster with some drivers when many widgets that
draw to the same backing store need to redraw. Because starts/ends of
QWindowsDirect2DDeviceContext are already refcounted this works out of the
box.

Change-Id: Ib48edceef6a1041ae0509587c77ac0caa8b29fc6
Reviewed-by: Risto Avila <risto.avila@digia.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Direct2D QPA: Correctly set active state in paint engine

Change-Id: I4eea073ad11ba8684212258b344c1f237598a9c5
Reviewed-by: Risto Avila <risto.avila@digia.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
iOS: scroll screen after hiding keyboard programatically

When the keyboard is told to hide, we resign first responder. If this
is done programatically on touch press, this will make the "hide keyboard
gesture" receive a touchesCancelled instead of a touchesEnded. Since we
didn't catch this from before, the gesture was left in a mixed state causing
the screen not to scroll when later showing the keyboard.

Change-Id: I70ed59710128a912097cd5bfbdd8f49b20b7934c
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@digia.com>
Add missing QT_NO_NETWORKPROXY guards around HTTP connect statements

Without these, a spew of connection warnings will occur when using HTTP
on Qt builds with QT_NO_NETWORKPROXY.

Change-Id: I330f6d98d1abdbadc57768dc48b8fab0ee1f6655
Reviewed-by: Oliver Wolff <oliver.wolff@digia.com>
Reviewed-by: Peter Hartmann <phartmann@blackberry.com>