Enable building ANGLE with D3D11 in -opengl dynamic builds.

Task-number: QTBUG-40193
Change-Id: If70943355d650cd3f20f4ff25fa09417a28a2b93
Reviewed-by: Andrew Knight <andrew.knight@digia.com>
tst_qwidget: Fix top level widget leaks.

Fix tests widgets leaking widgets and ensure it stays
that way by adding a check to cleanup().

Task-number: QTBUG-38858
Change-Id: I77a81d823c68cf0b4e51c2da55b1c473d6e4170b
Reviewed-by: Oliver Wolff <oliver.wolff@digia.com>