This sets

QStandardPaths::setTestModeEnabled(true);

so the tests don't clutter the regular appdata location, but put
everything in an easily cleanable .qttest folder.

Please don't create any new tests with QTEST_MAIN

There were also a small number of tests that werent built at all,
and consequently, when adding them back to the build, failed to
build. Those are removed.

CCMAIL:kimageshop@kde.org