Cleaning up the QPainter/arthur testing stuff

Cleaning up the QPainter/arthur testing stuff

This removes various remains of historical test tools, and the entire
tests/arthur directory. The living parts are now:
tests/auto/lancelot  - including the suite of qps scripts. The
                       script engine now lives here.
tests/baselineserver - moved to toplevel since not arthur-specific.
tests/manual/lance   - for manual running and editing of qps scripts.

Change-Id: I7c7f5df9197f4984a918dd1f9b31f42ee80d6152
Reviewed-on: http://codereview.qt.nokia.com/895
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Gunnar Sletta <gunnar.sletta@nokia.com>