ludus. Naming change in node impl.

Rename game type field to t.
ludus. Add access to node contained game type.

Remove the access to node contained game type in node impl. These are replaced with new access.
Add access to node contained game type.
Add private access interface to the contained game type to node.
Implement private access interface to the contained game type in node impl.
Changes to load tree to use new access.
Changes to test game to use new access to the root node.
ludus. Add log stream operator for node.
os. Add todo in resource manager destructor.

Need to check why there is a warning when trying to release the java asset manager in resource manager destructor.
ludus. Fix an issue in object destructor.

Do not call game on destroy object if the game interface is null.