Add QVERIFY_EXCEPTION_THROWN macro for testing exceptions using QtTest

New macro QVERIFY_EXCEPTION_THROWN may be used to check that some code
really throws an exception of specified type.

Change-Id: I7cf499c7c37a35407862bc604c6eb862c5f329d3
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Jason McDonald <macadder1@gmail.com>