Stop using setSharable in the Java-style mutable iterators

First and foremost, the STL-style iterators don't do this. Those don't
provide a guarantee that the container won't get shared again while the
iterator is active.

Second, there's no protection against a second mutable iterator being
created and resetting the sharable flag back to true.

[ChangeLog][Important behavior changes] The mutable Java-style iterators
like QListMutableIterator and QHashMutableIterator no longer set the
parent container to unsharable mode. If you create a copy of the
container being iterated on after the iterator, any changes done with
the iterator might affect the copy too.

Discussed-on: http://lists.qt-project.org/pipermail/development/2014-February/015724.html
Change-Id: Iccfe411d5558c85ae459cff944215614c392388e
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>
Remove friends of QEvent.

Introduce function to set the spontaneous flag to
QCoreApplicationPrivate to solve a few cases.

Change-Id: I7c1f1f3644defe00deea9cecb244ca258afd5b94
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>