The graph adadptors can be alteration observed.
In most cases it uses the adapted graph alteration notifiers.
Only special case is now the UndirGraphAdaptor, where
we have to proxy the signals from the graph.

The SubBidirGraphAdaptor is removed, because it doest not
gives more feature than the EdgeSubGraphAdaptor<UndirGraphAdaptor<Graph>>.

The ResGraphAdaptor is based on this composition.

@nodeset 

coordinates_x	coordinates_y	f	label	

-198	-73	2	7	

120	30	4	6	

-17	222	1	5	

328	147	1	4	

247	-179	0	3	

-28	-93	1	2	

-131	83	3	1	

@edgeset 

		label	

7	6	3	

1	6	2	

2	6	1	

4	5	10	

6	5	6	

3	4	9	

6	4	7	

2	3	12	

6	3	8	

7	2	4	

5	1	11	

7	1	5	

@nodes 

@edges 

@attributes 

@end