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: I73b99cd8e948dbebcdac30c4e5f2772eacb958ab
Reviewed-by: Jason McDonald <jason.mcdonald@nokia.com>