support generic single link list and double link list
define DOUBLE_LINK_LIST to 1 to enable double link list, support the API below now:
- link_list_init()
- link_list_append()
- link_list_find()
- link_list_delete()
- link_list_show_one()
- link_list_show_all()
see test_link_list for sample
TODO
TODO
TODO
support the API below now:
- split()
- split_free()