Mergeing extendermerge branch
Changes:
the extender system
resize for static size graph
UGraphExtender => UndirectGraphExtender
UGraphExtenders with changed meaning
Some UGraphExtender /SubUGraphExtenders, DirectUGraphExtender/
GridGraph => GridUGraph
radix sort to ansi compatible

@nodeset

label

0

1

2

3

4

5

6

@edgeset

        weight

0   3   1

0   4   1

1   5   1

5   2   1

6   2   1

0   1   1

2   1   1

3   4   1

4   5   1

5   6   1

@end