Revert "iOS: Update QIOSScreen::nativeOrientation() for iOS8"

This reverts commit f6c36917f15fda0066bf996c1d36ef6dace9f404.

Depends on 203ce7c5ce36f300750607b74b2d2429be2d4959
which can't go into 5.3 because it introduces new enum values.

Change-Id: I13040a7268fae4baeace244a3e75dc982d3a50b8
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@digia.com>
QCoreTextFontDatabase: reduce memory consumption

ATSFontNotify() allocates over 30MB for no apparent reason for
applications that don't register fonts.

Change-Id: I7bbc97f53b76be1e638de8ca0d1be3a08586cf00
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@digia.com>
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>
Add missing private headers warning

Change-Id: I7a4dd22ea3bcebf4c3ec3ad731628fd8f3c247e0
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Avoid adding widget to its own layout

Widgets and layouts added or inserted to a layout are checked for:
- Not being NULL
- Not being the parent widget of a layout or the layout itself,
  respectively

Without this commit, adding a widget to its own layout would result in a
CPU-hogging infinite loop. Now, a warning is written to stderr and the
add or insert function call is ignored.

The checks are implemented as public functions of QLayoutPrivate and
thus accessible in QLayout's descendants to be used in various
"addWidget", "insertWidget", etc functions.

Unlike 'classical' layouts like QGridLayout, QFormLayout does indeed
accept widgets that are NULL. To not break this behavior, any call for
the check functions first tests if the widget or layout, respectively,
to test is NULL or not and calls the check only in the latter case.

Automated tests for QBoxLayout, QGridLayout, and QFormLayout were added.
For an unpatched Qt 5.3, each of those automated tests will freeze as
explained in QTBUG-40609. For a fixed version, warning messages about
invalid parameters to addWidget/addLayout/... calls will be read by
QTest::ignoreMessage, resulting in a passed test.

Change-Id: I1522d5727e643da3f7c025755975aca9f482676d
Task-number: QTBUG-40609
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>