Bug 391198 - Scout 3.9 should be compatible to RAP 2.0

Adjusts Target files with RAP 2.1 (Kepler M6 contribution) update site.
Bug 400541: Create a "org.eclipse.scout.testing.commons" plugin.

Change imports in
- org.eclipse.scout.testing.client.runner.ScoutClientJobWrapperStatement
- org.eclipse.scout.testing.client.AbstractTestWithGuiScript
- org.eclipse.scout.rt.testing.server.runner.ScoutServerJobWrapperStatement

Add dependency to "org.eclipse.scout.rt.testing.commons" in:
- org.eclipse.scout.testing.client
- org.eclipse.scout.rt.testing.server

https://bugs.eclipse.org/bugs/show_bug.cgi?id=400541