Fix crash when re-creating QThreadData after initially destroying it

We destroy the thread data for the main thread when the QCoreApplication
is destructed, and then delete the pthread key for the thread data in
the global static destructor function 'destroy_current_thread_data_key'.

The user may have its own Q_DESTRUCTOR_FUNCTION though, which may or may
not run after we've destroyed the key. If it runs after we've destroyed
the key, we'll end up trying to re-create the tread-data, as expected,
but set_thread_data() will fail to persist it, as pthread_setspecific
is called with an invalid key. The result is an infinite recursion:

...
6  in QThreadData::current () at qthread_unix.cpp:216
7  in QObject::QObject (this=0x48e1b30, dd=@0x48e1b40, parent=0x0) at qobject.cpp:703
8  in QThread::QThread (this=0x48e1b30, dd=@0x48e1b40, parent=0x0) at qthread.cpp:396
9  in QAdoptedThread::QAdoptedThread (this=0x48e1b30, data=0x48e1af0) at qthread.cpp:120
10 in QAdoptedThread::QAdoptedThread (this=0x48e1b30, data=0x48e1af0) at qthread.cpp:130
11 in QThreadData::current () at qthread_unix.cpp:219
12 in QObject::QObject (this=0x48e1a20, dd=@0x48e1a30, parent=0x0) at qobject.cpp:703
...

To solve this, we reset current_thread_data_once when destroying the key,
so that subsequent calls to pthread_once to potentially create the key
will call create_current_thread_data_key once more. This means we'll leak
the key for this particular use-case, since we don't end up calling
pthread_key_delete a second time, but this leak is small and happens
typically only for a short duration during application shutdown.

Change-Id: I580484a3239849e891172e24e7f77b75afd2c51b
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
BlackBerry: fix delayed root window posting on OpenGL

The delayed root window posting introduced by
77a06e7e6c517003 broke the OpenGL support. In that patch, the posting of
the root window is trigerred by QQnxRasterRasterBackingStore's call to
QQnxWindow::post(), that obviously does not happen when OpenGL is enabled,
therefore requiring the OpenGL context to explicitly post() the root window.

Change-Id: Ifd302c1dde612a03b79c778ec4586aa70f88260d
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>
QSystemLocale: Fix the time format on BlackBerry 10

The time format should depend on the device settings (24 hour format)

Change-Id: I452d9b7158d39c4a657adfd9e64c99549eeda4ff
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Rafael Roquetto <rafael.roquetto@kdab.com>