WTHDW: Avoid unnecessary local reference to list of open windows.

In SetActiveWindow, we have a local reference for the list of open windows.
However, when inserting window handle we create a new reference. This is
unnecessary and the patch fixes it.
EventConverter: Ensure member variables are properly initialized.

EventConverterInProcess doesn't initialize member variable output_observer_
to NULL during initialization phase. This patch fixes it.
Add support for RPM build