Execute the test in a temporary directory, purge remaining files
except the special readonly-files in cleanup().
Avoid repeated invocation of QFINDTESTDATA() by assigning to
member variables.
Do more checks in rename(), check on contents of file.
Generally, use more QVERIFY2, print error messages.
Task-number: QTBUG-3570
Change-Id: Ibd0e11a361208a716ea3efbcca76adeda70e061a
Reviewed-by: David Faure (KDE) <faure@kde.org>
43ee10518a