Return "winphone" and "winrt" for Qt.platform.os when appropriate

Task-number: QTBUG-38532
Change-Id: I33b4fe5bb61baf9df3ca472424ca631172bf70fb
Reviewed-by: J-P Nurmi <jpnurmi@digia.com>
Reviewed-by: Oliver Wolff <oliver.wolff@digia.com>
Be more verbose about actual results in tst_qqmlprofilerservice

QCOMPARE and QVERIFY2 are clearly superior to QVERIFY when comparing
values in tests.

Change-Id: Ia860d6f087680066fbe0ffa311b5557e77f1720c
Reviewed-by: Kai Koehne <kai.koehne@digia.com>