Add some debugging information to diagnose bug.

Task-number: QTBUG-32927

Change-Id: I7d0a1ad9eeb63ac0ec28483106f42109ed1a834c
Reviewed-by: Sergio Ahumada <sergio.ahumada@digia.com>
Don't assume Q_OS_UNIX means we support QEventLoop::X11ExcludeTimers

A QCoreApplication may run a different event dispatcher, such as the
QEventDispatcherBlackberry, and QGuiApplications will have the GUI
dispatcher provided by the QPA plugin, such as QCocoaEventDispatcher.

Neither support X11ExcludeTimers.

Change-Id: Id5ea1c7dd74a127e13fa4d2eaa9a1bd2715a9dbb
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>
Add auto-test for running the QEventLoop test with the GUI dispatcher

Follows a similar include-pattern as the qguieventdispatcher test.

Change-Id: Ie8669a5bc155abd6687e81526f2b95d0d19b009e
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>