Because of separation of openide into pieces the TopManager.getWindowManager()
should be deprecated and replaced by WindowManager.getDefault() that will use
the Lookup to initialize the engine.
implemented in main trunk. Openide spec version grown to 2.10.
WindowManagerImpl.getDefault renamed to getInstance.
Verified and tests in the trunk changed to use it.
Resolved for 3.4.x or earlier, no new info since then -> closing.