Initial structure.

git-svn-id: https://192.168.1.100:4343/svn/data_structure_repo@1 0dde81f0-0e83-1f4f-a68e-81e57759cbb0
link list

git-svn-id: https://192.168.1.100:4343/svn/data_structure_repo@2 0dde81f0-0e83-1f4f-a68e-81e57759cbb0
link list

git-svn-id: https://192.168.1.100:4343/svn/data_structure_repo@3 0dde81f0-0e83-1f4f-a68e-81e57759cbb0
1.create link list
2.add node

git-svn-id: https://192.168.1.100:4343/svn/data_structure_repo@4 0dde81f0-0e83-1f4f-a68e-81e57759cbb0
1.see add_node() for better understanding of point as parameter.
2.add del_node() function.

git-svn-id: https://192.168.1.100:4343/svn/data_structure_repo@5 0dde81f0-0e83-1f4f-a68e-81e57759cbb0