Restore Fluid BT visualizer when game is stopped and restarted

[ashblue]

It would be nice if the visualizer could restore the last selected tree on stop and play. Somewhat annoying to have to re-click the BT button every time you play and stop.

To do this the visualizer will need to track the game object path in the hierarchy and the field name that contains the BT object. This can all be done when the BT button is clicked. Later, when the game is running attempt to use this information (stored locally) to try and restore the BT window with a recurring delay if there is currently no active BT being displayed.