Set the Qt API level to compatibility mode in all tests.

Set the Qt API level to compatibility mode in all tests.

Qt 5.0 beta requires changing the default to the 5.0 API, disabling
the deprecated code. However, tests should test (and often do) the
compatibility API too, so turn it back on.

Task-number: QTBUG-25053
Change-Id: Iab3d9fa844e74b7f8a17dbe1c26f9df6fa8dfadc
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>