Changed the API of the "Dao.Tree" so that it looks a bit more similar to "Data.Map" or "Data.Set" in the "containers" package.
Comments in 'Dao.Object.AST.AST_Script' script expressions (which are not at the top level) were failing to parse. I needed to add a new node to the AST for comments at the script expression level.  The new node is 'Dao.Object.AST.AST_Comment', and all of the associated instantiations are also ready.